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Search: a352520 -id:a352520
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Triangle T(n,k) read by rows: T(n,k) is the number of compositions of n with k parts p at position p (fixed points), n>=0, 0<=k<=n.
+10
43
1, 0, 1, 1, 1, 0, 2, 1, 1, 0, 3, 4, 1, 0, 0, 6, 7, 3, 0, 0, 0, 11, 16, 4, 1, 0, 0, 0, 22, 29, 12, 1, 0, 0, 0, 0, 42, 60, 23, 3, 0, 0, 0, 0, 0, 82, 120, 47, 7, 0, 0, 0, 0, 0, 0, 161, 238, 100, 12, 1, 0, 0, 0, 0, 0, 0, 316, 479, 198, 30, 1, 0, 0, 0, 0, 0, 0, 0, 624, 956, 404, 61, 3, 0, 0, 0, 0, 0, 0, 0, 0, 1235, 1910, 818, 126, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0
OFFSET
0,7
COMMENTS
T(n*(n+3)/2,n) = A227682(n).
From Vaclav Kotesovec, Sep 07 2014: (Start)
In general, column k is asymptotic to c(k) * 2^n. The constants c(k) numerically:
c(0) = 0.144394047543301210639449860964615390044455952420342... = A048651/2
c(1) = 0.231997216225445223894202367545783700531838988546098... = c(0)*A065442
c(2) = 0.104261929557371534733906196116707679501974368826074...
c(3) = 0.017956317806894073430249112172514186063327165575720...
c(4) = 0.001343254222922697613125145839110293324517874530073...
c(5) = 0.000046459767012163920051487037952792359225887287888...
c(6) = 0.000000768651747857094917953943327540619110335556499...
c(7) = 0.000000006200599904985793344094393321042983316604040...
c(8) = 0.000000000024656652167851516076173236693314090168122...
c(9) = 0.000000000000048633746319332356416193899916110113745...
c(10)= 0.000000000000000047750743608910618576944191079881479...
c(20)= 1.05217230403079700467566...*10^(-63)
For big k is c(k) ~ m * 2^(-k*(k+1)/2), where m = 1/(4*c(0)) = 1/(2*A048651) = 1.7313733097275318...
(End)
REFERENCES
M. Archibald, A. Blecher and A. Knopfmacher, Fixed points in compositions and words, accepted by the Journal of Integer Sequences.
LINKS
Joerg Arndt and Alois P. Heinz, Table of n, a(n) for n = 0..10010 (rows 0..140, flattened)
M. Archibald, A. Blecher, and A. Knopfmacher, Fixed Points in Compositions and Words, J. Int. Seq., Vol. 23 (2020), Article 20.11.1.
EXAMPLE
Triangle starts:
00: 1,
01: 0, 1,
02: 1, 1, 0,
03: 2, 1, 1, 0,
04: 3, 4, 1, 0, 0,
05: 6, 7, 3, 0, 0, 0,
06: 11, 16, 4, 1, 0, 0, 0,
07: 22, 29, 12, 1, 0, 0, 0, 0,
08: 42, 60, 23, 3, 0, 0, 0, 0, 0,
09: 82, 120, 47, 7, 0, 0, 0, 0, 0, 0,
10: 161, 238, 100, 12, 1, 0, 0, 0, 0, 0, 0,
11: 316, 479, 198, 30, 1, 0, 0, 0, 0, 0, 0, 0,
12: 624, 956, 404, 61, 3, 0, 0, 0, 0, 0, 0, 0, 0,
13: 1235, 1910, 818, 126, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0,
14: 2449, 3817, 1652, 258, 16, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
15: 4864, 7633, 3319, 537, 30, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
...
From Gus Wiseman, Apr 03 2022: (Start)
Row n = 5 counts the following compositions (empty columns indicated by dots):
(5) (14) (113) . . .
(23) (32) (122)
(41) (131) (1211)
(212) (221)
(311) (1112)
(2111) (1121)
(11111)
(End)
MAPLE
b:= proc(n, i) option remember; `if`(n=0, 1, expand(
add(b(n-j, i+1)*`if`(i=j, x, 1), j=1..n)))
end:
T:= n-> (p-> seq(coeff(p, x, i), i=0..n))(b(n, 1)):
seq(T(n), n=0..15);
MATHEMATICA
b[n_, i_] := b[n, i] = If[n == 0, 1, Expand[Sum[b[n-j, i+1]*If[i == j, x, 1], {j, 1, n}]]]; T[n_] := Function[{p}, Table[Coefficient[p, x, i], {i, 0, n}]][b[n, 1]]; Table[T[n], {n, 0, 15}] // Flatten (* Jean-François Alcover, Jan 06 2015, after Alois P. Heinz *)
pq[y_]:=Length[Select[Range[Length[y]], #==y[[#]]&]];
Table[Length[Select[Join@@Permutations/@IntegerPartitions[n], pq[#]==k&]], {n, 0, 9}, {k, 0, n}] (* Gus Wiseman, Apr 03 2022 *)
CROSSREFS
Row sums are A011782.
The version for permutations is A008290.
The version with all zeros removed is A238350.
The version for reversed partitions is A238352.
The corresponding rank statistic is A352512, nonfixed A352513.
The version for nonfixed points is A352523, A352520 (k=1).
Below: comps = compositions, first = column k=0, stat = rank statistic.
- A352521 counts comps by strong nonexcedances, first A219282, stat A352514.
- A352522 counts comps by weak nonexcedances, first A238874, stat A352515.
- A352524 counts comps by strong excedances, first A008930, stat A352516.
- A352525 counts comps by weak excedances, A177510 (k=1), stat A352517.
KEYWORD
nonn,tabl
AUTHOR
Joerg Arndt and Alois P. Heinz, Feb 25 2014
STATUS
approved
Number of integer compositions of n with exactly k nonfixed points (parts not on the diagonal).
+10
25
1, 1, 0, 0, 2, 0, 1, 1, 2, 0, 0, 4, 2, 2, 0, 0, 5, 5, 4, 2, 0, 1, 3, 12, 8, 6, 2, 0, 0, 7, 14, 19, 14, 8, 2, 0, 0, 8, 21, 33, 32, 22, 10, 2, 0, 0, 9, 30, 54, 63, 54, 32, 12, 2, 0, 1, 6, 47, 80, 116, 116, 86, 44, 14, 2, 0, 0, 11, 53, 129, 194, 229, 202, 130, 58, 16, 2, 0
OFFSET
0,5
COMMENTS
A nonfixed point in a composition c is an index i such that c_i != i.
EXAMPLE
Triangle begins:
1
1 0
0 2 0
1 1 2 0
0 4 2 2 0
0 5 5 4 2 0
1 3 12 8 6 2 0
0 7 14 19 14 8 2 0
0 8 21 33 32 22 10 2 0
0 9 30 54 63 54 32 12 2 0
1 6 47 80 116 116 86 44 14 2 0
For example, row n = 6 counts the following compositions (empty column indicated by dot):
(123) (6) (24) (231) (2112) (21111) .
(15) (33) (312) (2121) (111111)
(42) (51) (411) (3111)
(114) (1113) (11112)
(132) (1122) (11121)
(141) (1311) (11211)
(213) (2211)
(222) (12111)
(321)
(1131)
(1212)
(1221)
MATHEMATICA
pnq[y_]:=Length[Select[Range[Length[y]], #!=y[[#]]&]];
Table[Length[Select[Join@@Permutations/@IntegerPartitions[n], pnq[#]==k&]], {n, 0, 9}, {k, 0, n}]
CROSSREFS
Column k = 0 is A010054.
Row sums are A011782.
The version for permutations is A098825.
The corresponding rank statistic is A352513.
Column k = 1 is A352520.
A238349 counts comps by fixed points, first col A238351, rank stat A352512.
A352486 gives the nonfixed points of A122111, counted by A330644.
A352521 counts comps by strong nonexcedances, first A219282, stat A352514.
A352522 counts comps by weak nonexcedances, first col A238874, stat A352515.
A352524 counts comps by strong excedances, first col A008930, stat A352516.
A352525 counts comps by weak excedances, first col A177510, stat A352517.
KEYWORD
nonn
AUTHOR
Gus Wiseman, Mar 26 2022
STATUS
approved
Number of compositions (p0, p1, p2, ...) of n with pi - p0 <= i and pi >= p0.
+10
24
1, 1, 2, 3, 5, 8, 14, 25, 46, 87, 167, 324, 634, 1248, 2466, 4887, 9706, 19308, 38455, 76659, 152925, 305232, 609488, 1217429, 2432399, 4860881, 9715511, 19421029, 38826059, 77626471, 155211785, 310357462, 620608652, 1241046343, 2481817484, 4963191718, 9925669171, 19850186856, 39698516655, 79394037319
OFFSET
0,3
COMMENTS
a(0)=1, otherwise row sums of A179748.
For n>=1 cumulative sums of A008930.
a(n) is proportional to A048651*A000079. The error (a(n)-A048651*A000079) divided by sequence A186425 tends to the golden ratio A001622. This can be seen when using about 1000 decimals of the constant A048651 = 0.2887880950866024212... - [Mats Granvik, Jan 01 2015]
From Gus Wiseman, Mar 31 2022: (Start)
Also the number of integer compositions of n with exactly one part on or above the diagonal. For example, the a(1) = 1 through a(5) = 8 compositions are:
(1) (2) (3) (4) (5)
(11) (21) (31) (41)
(111) (112) (212)
(211) (311)
(1111) (1112)
(1121)
(2111)
(11111)
(End)
FORMULA
G.f.: 1 + q/(1-q) * sum(n>=0, q^n * prod(k=1..n, (1-q^k)/(1-q) ) ). [Joerg Arndt, Mar 24 2014]
EXAMPLE
From Joerg Arndt, Mar 24 2014: (Start)
The a(7) = 25 such compositions are:
01: [ 1 1 1 1 1 1 1 ]
02: [ 1 1 1 1 1 2 ]
03: [ 1 1 1 1 2 1 ]
04: [ 1 1 1 1 3 ]
05: [ 1 1 1 2 1 1 ]
06: [ 1 1 1 2 2 ]
07: [ 1 1 1 3 1 ]
08: [ 1 1 1 4 ]
09: [ 1 1 2 1 1 1 ]
10: [ 1 1 2 1 2 ]
11: [ 1 1 2 2 1 ]
12: [ 1 1 2 3 ]
13: [ 1 1 3 1 1 ]
14: [ 1 1 3 2 ]
15: [ 1 2 1 1 1 1 ]
16: [ 1 2 1 1 2 ]
17: [ 1 2 1 2 1 ]
18: [ 1 2 1 3 ]
19: [ 1 2 2 1 1 ]
20: [ 1 2 2 2 ]
21: [ 1 2 3 1 ]
22: [ 2 2 3 ]
23: [ 2 3 2 ]
24: [ 3 4 ]
25: [ 7 ]
(End)
MAPLE
A179748 := proc(n, k) option remember; if k= 1 then 1; elif k> n then 0 ; else add( procname(n-i, k-1), i=1..k-1) ; end if; end proc:
A177510 := proc(n) add(A179748(n, k), k=1..n) ; end proc:
seq(A177510(n), n=1..20) ; # R. J. Mathar, Dec 14 2010
MATHEMATICA
Clear[t, nn]; nn = 39; t[n_, 1] = 1; t[n_, k_] := t[n, k] = If[n >= k, Sum[t[n - i, k - 1], {i, 1, k - 1}], 0]; Table[Sum[t[n, k], {k, 1, n}], {n, 1, nn}] (* Mats Granvik, Jan 01 2015 *)
pdw[y_]:=Length[Select[Range[Length[y]], #<=y[[#]]&]]; Table[Length[Select[Join@@Permutations/@IntegerPartitions[n], pdw[#]==1&]], {n, 0, 10}] (* Gus Wiseman, Mar 31 2022 *)
PROG
(Sage)
@CachedFunction
def T(n, k): # A179748
if n == 0: return int(k==0);
if k == 1: return int(n>=1);
return sum( T(n-i, k-1) for i in [1..k-1] );
# to display triangle A179748 including column zero = [1, 0, 0, 0, ...]:
#for n in [0..10]: print([ T(n, k) for k in [0..n] ])
def a(n): return sum( T(n, k) for k in [0..n] )
print([a(n) for n in [0..66]])
# Joerg Arndt, Mar 24 2014
(PARI) N=66; q='q+O('q^N); Vec( 1 + q/(1-q) * sum(n=0, N, q^n * prod(k=1, n, (1-q^k)/(1-q) ) ) ) \\ Joerg Arndt, Mar 24 2014
CROSSREFS
Cf. A238859 (compositions with subdiagonal growth), A238876 (partitions with subdiagonal growth), A001227 (partitions into distinct parts with subdiagonal growth).
Cf. A238860 (partitions with superdiagonal growth), A238861 (compositions with superdiagonal growth), A000009 (partitions into distinct parts have superdiagonal growth by definition).
The version for partitions is A001477, strong A002620.
The version for permutations is A057427, strong A000295.
The opposite version is A238874, first column of A352522.
The version for fixed points is A240736, nonfixed A352520.
The strong version is A351983, column k=1 of A352524.
This is column k = 1 of A352525.
A238349 counts compositions by fixed points, first col A238351.
A352517 counts weak excedances of standard compositions.
KEYWORD
nonn
AUTHOR
Mats Granvik, Dec 11 2010
EXTENSIONS
New name and a(0) = 1 prepended, Joerg Arndt, Mar 24 2014
STATUS
approved
Number of fixed points in the n-th composition in standard order.
+10
20
0, 1, 0, 1, 0, 0, 2, 1, 0, 0, 1, 0, 1, 2, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 2, 2, 2, 1, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 3, 2, 2, 2, 1, 2, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 2, 1, 1
OFFSET
0,7
COMMENTS
The k-th composition in standard order (graded reverse-lexicographic, A066099) is obtained by taking the set of positions of 1's in the reversed binary expansion of k, prepending 0, taking first differences, and reversing again. This gives a bijective correspondence between nonnegative integers and integer compositions. See also A000120, A059893, A070939, A114994, A225620.
A fixed point of composition c is an index i such that c_i = i.
FORMULA
A000120(n) = A352512(n) + A352513(n).
EXAMPLE
The 169th composition in standard order is (2,2,3,1), with fixed points {2,3}, so a(169) = 2.
MATHEMATICA
stc[n_]:=Differences[Prepend[Join@@ Position[Reverse[IntegerDigits[n, 2]], 1], 0]]//Reverse;
pq[y_]:=Length[Select[Range[Length[y]], #==y[[#]]&]];
Table[pq[stc[n]], {n, 0, 100}]
CROSSREFS
The version counting permutations is A008290, unfixed A098825.
The triangular version is A238349, first column A238351.
Unfixed points are counted by A352513, triangle A352523, first A352520.
A011782 counts compositions.
A088902 gives the fixed points of A122111, counted by A000700.
A352521 counts comps by strong nonexcedances, first A219282, stat A352514.
A352522 counts comps by weak nonexcedances, first col A238874, stat A352515.
A352524 counts comps by strong excedances, first col A008930, stat A352516.
A352525 counts comps by weak excedances, first col A177510, stat A352517.
KEYWORD
nonn
AUTHOR
Gus Wiseman, Mar 26 2022
STATUS
approved
Number of nonfixed points in the n-th composition in standard order.
+10
20
0, 0, 1, 1, 1, 2, 0, 2, 1, 2, 1, 3, 1, 1, 2, 3, 1, 2, 1, 3, 2, 2, 3, 4, 1, 2, 1, 2, 1, 3, 3, 4, 1, 2, 1, 3, 2, 2, 3, 4, 2, 3, 2, 3, 2, 4, 4, 5, 1, 2, 2, 3, 0, 2, 2, 3, 2, 2, 3, 4, 3, 4, 4, 5, 1, 2, 1, 3, 2, 2, 3, 4, 2, 3, 2, 3, 2, 4, 4, 5, 2, 3, 3, 4, 1, 3, 3
OFFSET
0,6
COMMENTS
The k-th composition in standard order (graded reverse-lexicographic, A066099) is obtained by taking the set of positions of 1's in the reversed binary expansion of k, prepending 0, taking first differences, and reversing again. This gives a bijective correspondence between nonnegative integers and integer compositions. See also A000120, A059893, A070939, A114994, A225620.
A nonfixed point in a composition c is an index i such that c_i != i.
FORMULA
A000120(n) = A352512(n) + A352513(n).
EXAMPLE
The 169th composition in standard order is (2,2,3,1), with nonfixed points {1,4}, so a(169) = 2.
MATHEMATICA
stc[n_]:=Differences[Prepend[Join@@ Position[Reverse[IntegerDigits[n, 2]], 1], 0]]//Reverse;
pnq[y_]:=Length[Select[Range[Length[y]], #!=y[[#]]&]];
Table[pnq[stc[n]], {n, 0, 100}]
CROSSREFS
The version counting permutations is A098825, fixed A008290.
Fixed points are counted by A352512, triangle A238349, first A238351.
The triangular version is A352523, first nontrivial column A352520.
A011782 counts compositions.
A352486 gives the nonfixed points of A122111, counted by A330644.
A352521 counts comps by strong nonexcedances, first A219282, stat A352514.
A352522 counts comps by weak nonexcedances, first col A238874, stat A352515.
A352524 counts comps by strong excedances, first col A008930, stat A352516.
A352525 counts comps by weak excedances, first col A177510, stat A352517.
KEYWORD
nonn
AUTHOR
Gus Wiseman, Mar 27 2022
STATUS
approved
Triangle read by rows where T(n,k) is the number of integer compositions of n with k weak nonexcedances (parts on or below the diagonal).
+10
20
1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 3, 1, 2, 1, 2, 3, 4, 3, 3, 1, 3, 4, 8, 6, 6, 4, 1, 4, 7, 12, 13, 12, 10, 5, 1, 5, 13, 16, 26, 24, 22, 15, 6, 1, 7, 19, 27, 43, 48, 46, 37, 21, 7, 1, 10, 26, 47, 68, 90, 93, 83, 58, 28, 8, 1, 14, 36, 77, 109, 159, 180, 176, 141
OFFSET
0,12
LINKS
EXAMPLE
Triangle begins:
1
0 1
1 0 1
1 1 1 1
1 3 1 2 1
2 3 4 3 3 1
3 4 8 6 6 4 1
4 7 12 13 12 10 5 1
5 13 16 26 24 22 15 6 1
7 19 27 43 48 46 37 21 7 1
10 26 47 68 90 93 83 58 28 8 1
For example, row n = 6 counts the following compositions:
(6) (15) (114) (123) (1113) (11112) (111111)
(24) (42) (132) (1311) (1122) (11121)
(33) (51) (141) (2112) (1131) (11211)
(231) (213) (2121) (1212) (12111)
(222) (2211) (1221)
(312) (3111) (21111)
(321)
(411)
MATHEMATICA
pw[y_]:=Length[Select[Range[Length[y]], #>=y[[#]]&]];
Table[Length[Select[Join@@Permutations/@IntegerPartitions[n], pw[#]==k&]], {n, 0, 15}, {k, 0, n}]
PROG
(PARI) T(n)={my(v=vector(n+1, i, i==1), r=v); for(k=1, n, v=vector(#v, j, sum(i=1, j-1, if(k>=i, x, 1)*v[j-i])); r+=v); [Vecrev(p) | p<-r]}
{ my(A=T(10)); for(i=1, #A, print(A[i])) } \\ Andrew Howroyd, Jan 19 2023
CROSSREFS
Row sums are A011782.
The strong version for partitions is A114088.
The opposite version for partitions is A115994.
The version for permutations is A123125, strong A173018.
Column k = 0 is A238874.
The corresponding rank statistic is A352515.
The strong version is A352521, first column A219282, rank statistic A352514.
The strong opposite is A352524, first col A008930, rank statistic A352516.
The opposite version is A352525, first col A177510, rank statistic A352517.
A000041 counts integer partitions, strict A000009.
A008292 is the triangle of Eulerian numbers (version without zeros).
A238349 counts comps by fixed points, first col A238351, rank stat A352512.
A352488 lists the weak nonexcedance set of A122111.
A352523 counts comps by unfixed points, first A352520, rank stat A352513.
KEYWORD
nonn,tabl
AUTHOR
Gus Wiseman, Mar 22 2022
STATUS
approved
Irregular triangle read by rows where T(n,k) is the number of integer compositions of n with k weak excedances (parts on or above the diagonal), all zeros removed.
+10
20
1, 1, 2, 3, 1, 5, 3, 8, 8, 14, 17, 1, 25, 35, 4, 46, 70, 12, 87, 137, 32, 167, 268, 76, 1, 324, 525, 170, 5, 634, 1030, 367, 17, 1248, 2026, 773, 49, 2466, 3999, 1598, 129, 4887, 7914, 3267, 315, 1, 9706, 15695, 6631, 730, 6, 19308, 31181, 13393, 1631, 23
OFFSET
0,3
LINKS
EXAMPLE
Triangle begins:
1
1
2
3 1
5 3
8 8
14 17 1
25 35 4
46 70 12
87 137 32
167 268 76 1
324 525 170 5
For example, row n = 6 counts the following compositions:
(6) (15) (123)
(51) (24)
(312) (33)
(411) (42)
(1113) (114)
(1122) (132)
(2112) (141)
(2121) (213)
(3111) (222)
(11112) (231)
(11121) (321)
(11211) (1131)
(21111) (1212)
(111111) (1221)
(1311)
(2211)
(12111)
MATHEMATICA
pdw[y_]:=Length[Select[Range[Length[y]], #<=y[[#]]&]];
DeleteCases[Table[Length[Select[Join@@ Permutations/@IntegerPartitions[n], pdw[#]==k&]], {n, 0, 10}, {k, 0, n}], 0, {2}]
PROG
(PARI) T(n)={my(v=vector(n+1, i, i==1), r=v); for(k=1, n, v=vector(#v, j, sum(i=1, j-1, if(k<=i, x, 1)*v[j-i])); r+=v); r[1]=x; [Vecrev(p) | p<-r/x]}
{ my(A=T(10)); for(i=1, #A, print(A[i])) } \\ Andrew Howroyd, Jan 19 2023
CROSSREFS
Row sums are A011782.
The version for partitions is A115994.
The version for permutations is A123125, strong A173018.
Column k = 1 is A177510.
The corresponding rank statistic is A352517.
The strong opposite is A352521, first col A219282, rank statistic A352514.
The opposite version is A352522, first col A238874, rank statistic A352515.
The strong version is A352524, first column A008930, rank statistic A352516.
A008292 is the triangle of Eulerian numbers (version without zeros).
A238349 counts comps by fixed points, first col A238351, rank stat A352512.
A352489 lists the weak excedance set of A122111.
A352523 counts comps by unfixed points, first A352520, rank stat A352513.
KEYWORD
nonn,tabf
AUTHOR
Gus Wiseman, Mar 22 2022
STATUS
approved
Triangle read by rows where T(n,k) is the number of integer compositions of n with k strong nonexcedances (parts below the diagonal).
+10
18
1, 1, 0, 1, 1, 0, 2, 1, 1, 0, 3, 2, 2, 1, 0, 4, 5, 3, 3, 1, 0, 6, 8, 7, 6, 4, 1, 0, 9, 12, 15, 12, 10, 5, 1, 0, 13, 19, 27, 25, 22, 15, 6, 1, 0, 18, 32, 43, 51, 46, 37, 21, 7, 1, 0, 25, 51, 70, 94, 94, 83, 58, 28, 8, 1, 0, 35, 77, 117, 162, 184, 176, 141, 86, 36, 9, 1, 0
OFFSET
0,7
EXAMPLE
Triangle begins:
1
1 0
1 1 0
2 1 1 0
3 2 2 1 0
4 5 3 3 1 0
6 8 7 6 4 1 0
9 12 15 12 10 5 1 0
13 19 27 25 22 15 6 1 0
18 32 43 51 46 37 21 7 1 0
25 51 70 94 94 83 58 28 8 1 0
For example, row n = 6 counts the following compositions (empty column indicated by dot):
(6) (51) (312) (1113) (11112) (111111) .
(15) (114) (411) (1122) (11121)
(24) (132) (1131) (2112) (11211)
(33) (141) (1212) (2121) (21111)
(42) (213) (1221) (3111)
(123) (222) (1311) (12111)
(231) (2211)
(321)
MATHEMATICA
pa[y_]:=Length[Select[Range[Length[y]], #>y[[#]]&]];
Table[Length[Select[Join@@Permutations/@IntegerPartitions[n], pa[#]==k&]], {n, 0, 15}, {k, 0, n}]
PROG
(PARI) T(n)={my(v=vector(n+1, i, i==1), r=v); for(k=1, n, v=vector(#v, j, sum(i=1, j-1, if(k>i, x, 1)*v[j-i])); r+=v); vector(#v, i, Vecrev(r[i], i))}
{ my(A=T(10)); for(i=1, #A, print(A[i])) } \\ Andrew Howroyd, Jan 19 2023
CROSSREFS
Row sums are A011782.
The version for partitions is A114088.
Row sums without the last term are A131577.
The version for permutations is A173018.
Column k = 0 is A219282.
The corresponding rank statistic is A352514.
The weak version is A352522, first column A238874, rank statistic A352515.
The opposite version is A352524, first column A008930, rank stat A352516.
The weak opposite version is A352525, first col A177510, rank stat A352517.
A008292 is the triangle of Eulerian numbers (version without zeros).
A238349 counts comps by fixed points, first col A238351, rank stat A352512.
A352490 is the strong nonexcedance set of A122111.
A352523 counts comps by nonfixed points, first A352520, rank stat A352513.
KEYWORD
nonn,tabl
AUTHOR
Gus Wiseman, Mar 22 2022
EXTENSIONS
Terms a(66) and beyond from Andrew Howroyd, Jan 19 2023
STATUS
approved
Irregular triangle read by rows where T(n,k) is the number of integer compositions of n with k excedances (parts above the diagonal), all zeros removed.
+10
18
1, 1, 1, 1, 2, 2, 3, 5, 6, 9, 1, 11, 18, 3, 21, 35, 8, 41, 67, 20, 80, 131, 44, 1, 157, 257, 94, 4, 310, 505, 197, 12, 614, 996, 406, 32, 1218, 1973, 825, 80, 2421, 3915, 1669, 186, 1, 4819, 7781, 3364, 415, 5, 9602, 15486, 6762, 901, 17, 19147, 30855, 13567, 1918, 49
OFFSET
0,5
LINKS
EXAMPLE
Triangle begins:
1
1
1 1
2 2
3 5
6 9 1
11 18 3
21 35 8
41 67 20
80 131 44 1
157 257 94 4
310 505 197 12
614 996 406 32
For example, row n = 5 counts the following compositions:
(113) (5) (23)
(122) (14)
(1112) (32)
(1121) (41)
(1211) (131)
(11111) (212)
(221)
(311)
(2111)
MATHEMATICA
pd[y_]:=Length[Select[Range[Length[y]], #<y[[#]]&]];
DeleteCases[Table[Length[Select[Join@@ Permutations/@IntegerPartitions[n], pd[#]==k&]], {n, 0, 10}, {k, 0, n}], 0, {2}]
PROG
(PARI)
S(v, u)={vector(#v, k, sum(i=1, k-1, v[k-i]*u[i]))}
T(n)={my(v=vector(1+n), s); v[1]=1; s=v; for(i=1, n, v=S(v, vector(n, j, if(j>i, 'x, 1))); s+=v); [Vecrev(p) | p<-s]}
{ my(A=T(12)); for(n=1, #A, print(A[n])) } \\ Andrew Howroyd, Jan 02 2023
CROSSREFS
The version for permutations is A008292, weak A123125.
Column k = 0 is A008930.
Row sums are A011782.
The opposite version for partitions is A114088.
The weak version for partitions is A115994.
Column k = 1 is A351983.
The corresponding rank statistic is A352516.
The opposite version is A352521, first col A219282, rank statistic A352514.
The weak opposite version is A352522, first col A238874, rank stat A352515.
The weak version is A352525, first col (k = 1) A177510, rank stat A352517.
A238349 counts comps by fixed points, first col A238351, rank stat A352512.
A352487 lists the excedance set of A122111, opposite A352490.
A352523 counts comps by unfixed points, first A352520, rank stat A352513.
KEYWORD
nonn,tabf
AUTHOR
Gus Wiseman, Mar 22 2022
STATUS
approved
Numbers whose weakly increasing prime indices y have exactly one fixed point y(i) = i.
+10
13
2, 4, 8, 9, 10, 12, 14, 16, 22, 24, 26, 27, 28, 32, 34, 36, 38, 40, 44, 46, 48, 52, 58, 60, 62, 63, 64, 68, 70, 72, 74, 75, 76, 80, 81, 82, 86, 88, 92, 94, 96, 98, 99, 104, 106, 108, 110, 112, 116, 117, 118, 120, 122, 124, 125, 128, 130, 132, 134, 135, 136
OFFSET
1,1
COMMENTS
A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798.
EXAMPLE
The terms together with their prime indices begin:
2: {1} 36: {1,1,2,2} 74: {1,12}
4: {1,1} 38: {1,8} 75: {2,3,3}
8: {1,1,1} 40: {1,1,1,3} 76: {1,1,8}
9: {2,2} 44: {1,1,5} 80: {1,1,1,1,3}
10: {1,3} 46: {1,9} 81: {2,2,2,2}
12: {1,1,2} 48: {1,1,1,1,2} 82: {1,13}
14: {1,4} 52: {1,1,6} 86: {1,14}
16: {1,1,1,1} 58: {1,10} 88: {1,1,1,5}
22: {1,5} 60: {1,1,2,3} 92: {1,1,9}
24: {1,1,1,2} 62: {1,11} 94: {1,15}
26: {1,6} 63: {2,2,4} 96: {1,1,1,1,1,2}
27: {2,2,2} 64: {1,1,1,1,1,1} 98: {1,4,4}
28: {1,1,4} 68: {1,1,7} 99: {2,2,5}
32: {1,1,1,1,1} 70: {1,3,4} 104: {1,1,1,6}
34: {1,7} 72: {1,1,1,2,2} 106: {1,16}
For example, 63 is in the sequence because its prime indices {2,2,4} have a unique fixed point at the second position.
MATHEMATICA
pq[y_]:=Length[Select[Range[Length[y]], #==y[[#]]&]];
Select[Range[100], pq[Flatten[Cases[FactorInteger[#], {p_, k_}:>Table[PrimePi[p], {k}]]]]==1&]
CROSSREFS
* = unproved
These are the positions of 1's in A352822.
*The reverse version for no fixed points is A352826, counted by A064428.
*The reverse version is A352827, counted by A001522 (strict A352829).
The version for no fixed points is A352830, counted by A238394.
These partitions are counted by A352832, compositions A240736.
Allowing more than one fixed point gives A352872, counted by A238395.
A000700 counts self-conjugate partitions, ranked by A088902.
A001222 counts prime indices, distinct A001221.
A008290 counts permutations by fixed points, nonfixed A098825.
A056239 adds up prime indices, row sums of A112798 and A296150.
A115720 and A115994 count partitions by their Durfee square.
A238349 counts compositions by fixed points, complement A352523.
A238352 counts reversed partitions by fixed points.
A352833 counts partitions by fixed points.
KEYWORD
nonn
AUTHOR
Gus Wiseman, Apr 08 2022
STATUS
approved

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