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Search: a323450 -id:a323450
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Number of square plane partitions of n.
+10
13
1, 1, 1, 1, 2, 2, 4, 5, 8, 11, 16, 21, 31, 41, 57, 78, 108, 146, 202, 274, 375, 509, 690, 929, 1255, 1679, 2246, 2991, 3979, 5266, 6971, 9187, 12104, 15898, 20870, 27322, 35762, 46690, 60927, 79348, 103270, 134138, 174108, 225576, 291990, 377320, 487083
OFFSET
0,5
COMMENTS
Number of ways of writing n as a sum p(1,1) + p(1,2) + ... + p(1,k) + p(2,1) + ... + p(2,k) + ... + p(k,1) + ... + p(k,k) for some k so that in the square array {p(i,j)} the numbers are nonincreasing along rows and columns. All the p(i,j) are >= 1.
LINKS
FORMULA
G.f.: Sum_{k>=0} x^(k^2) / Product_{j=1..2k-1} (1-x^j)^min(j,2k-j). - Franklin T. Adams-Watters, Jun 14 2006
EXAMPLE
a(7) = 5:
7 41 32 31 22
. 11 11 21 21
a(10) = 16 from {{10}}, {{3, 2}, {3, 2}}, {{3, 3}, {2, 2}}, {{3, 3}, {3, 1}}, {{4, 1}, {4, 1}}, {{4, 2}, {2, 2}}, {{4, 2}, {3, 1}}, {{4, 3}, {2, 1}}, {{4, 4}, {1, 1}}, {{5, 1}, {3, 1}}, {{5, 2}, {2, 1}}, {{5, 3}, {1, 1}}, {{6, 1}, {2, 1}}, {{6, 2}, {1, 1}}, {{7, 1}, {1, 1}}, {{2, 1, 1}, {1, 1, 1}, {1, 1, 1}}
From Gus Wiseman, Jan 16 2019: (Start)
The a(10) = 16 square plane partitions:
[ten]
.
[32] [33] [33] [41] [42] [42] [43] [44] [51] [52] [53] [61] [62] [71]
[32] [22] [31] [41] [22] [31] [21] [11] [31] [21] [11] [21] [11] [11]
.
[211]
[111]
[111]
(End)
MATHEMATICA
Table[Sum[Length[Select[Union[Sort/@Tuples[IntegerPartitions[#, {Length[ptn]}]&/@ptn]], And@@OrderedQ/@Transpose[#]&]], {ptn, IntegerPartitions[n]}], {n, 30}] (* Gus Wiseman, Jan 16 2019 *)
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Dec 25 2003
EXTENSIONS
Corrected and extended by Wouter Meeussen, Dec 30 2003
a(21)-a(25) from John W. Layman, Jan 02 2004
More terms from Franklin T. Adams-Watters, Jun 14 2006
Name edited by Gus Wiseman, Jan 16 2019
STATUS
approved
Number of ways to fill a Young diagram with the prime indices of n such that all rows and columns are weakly increasing.
+10
13
1, 1, 1, 2, 1, 2, 1, 3, 2, 2, 1, 4, 1, 2, 2, 5, 1, 3, 1, 4, 2, 2, 1, 7, 2, 2, 3, 4, 1, 4, 1, 7, 2, 2, 2, 8, 1, 2, 2, 7, 1, 4, 1, 4, 4, 2, 1, 12, 2, 3, 2, 4, 1, 5, 2, 7, 2, 2, 1, 10, 1, 2, 4, 11, 2, 4, 1, 4, 2, 4, 1, 13, 1, 2, 3, 4, 2, 4, 1, 12, 5, 2, 1, 10, 2
OFFSET
1,4
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.
FORMULA
Sum_{A056239(n) = k} a(k) = A323450(n).
EXAMPLE
The a(96) = 19 tableaux:
111112
.
111 1111 1112 11111 11112
112 12 11 2 1
.
11 111 111 112 1111 1112
11 11 12 11 1 1
12 2 1 1 2 1
.
11 11 111 112
11 12 1 1
1 1 1 1
2 1 2 1
.
11 12
1 1
1 1
1 1
2 1
.
1
1
1
1
1
2
MATHEMATICA
primeMS[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];
facs[n_]:=If[n<=1, {{}}, Join@@Table[Map[Prepend[#, d]&, Select[facs[n/d], Min@@#>=d&]], {d, Rest[Divisors[n]]}]];
ptnplane[n_]:=Union[Map[primeMS, Join@@Permutations/@facs[n], {2}]];
Table[Length[Select[ptnplane[y], And[And@@LessEqual@@@#, And@@(LessEqual@@@Transpose[PadRight[#]/.(0->Infinity)])]&]], {y, 100}]
KEYWORD
nonn
AUTHOR
Gus Wiseman, Jan 16 2019
STATUS
approved
Number of ways to fill a Young diagram with the prime indices of n such that all rows and columns are strictly increasing.
+10
7
1, 1, 1, 0, 1, 2, 1, 0, 0, 2, 1, 0, 1, 2, 2, 0, 1, 1, 1, 0, 2, 2, 1, 0, 0, 2, 0, 0, 1, 4, 1, 0, 2, 2, 2, 0, 1, 2, 2, 0, 1, 4, 1, 0, 0, 2, 1, 0, 0, 1, 2, 0, 1, 0, 2, 0, 2, 2, 1, 0, 1, 2, 0, 0, 2, 4, 1, 0, 2, 4, 1, 0, 1, 2, 1, 0, 2, 4, 1, 0, 0, 2, 1, 0, 2, 2, 2
OFFSET
1,6
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.
FORMULA
Sum_{A056239(n) = k} a(k) = A323451(n).
EXAMPLE
The a(630) = 8 tableaux:
123 124 1234
24 23 2
.
12 12 123 124
23 24 2 2
4 3 4 3
.
12
2
3
4
MATHEMATICA
primeMS[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];
facs[n_]:=If[n<=1, {{}}, Join@@Table[Map[Prepend[#, d]&, Select[facs[n/d], Min@@#>=d&]], {d, Rest[Divisors[n]]}]];
ptnplane[n_]:=Union[Map[primeMS, Join@@Permutations/@facs[n], {2}]];
Table[Length[Select[ptnplane[y], And[And@@Less@@@#, And@@(Less@@@DeleteCases[Transpose[PadRight[#]], 0, {2}]), And@@(LessEqual@@@Transpose[PadRight[#]/.(0->Infinity)])]&]], {y, 100}]
KEYWORD
nonn
AUTHOR
Gus Wiseman, Jan 16 2019
STATUS
approved
Number of generalized Young tableaux with constant rows, weakly increasing columns, and entries summing to n.
+10
6
1, 1, 3, 5, 11, 16, 33, 47, 85, 126, 208, 299, 486, 685, 1050, 1496, 2221, 3097, 4523, 6239, 8901, 12219, 17093, 23202, 32120, 43200, 58899, 78761, 106210, 140786, 188192, 247689, 327965, 429183, 563592, 732730, 955851, 1235370, 1600205, 2057743, 2649254
OFFSET
0,3
COMMENTS
For strictly increasing columns, see A100883.
EXAMPLE
The a(5) = 16 tableaux:
5 1 1 1 1 1
.
1 2 1 1 1 1 1 1 1 1 1 1 1 1
4 3 3 2 1 1 1
.
1 1 1 1 1 1 1 1 1
1 2 1 1 1 1
3 2 2 1 1
.
1 1 1
1 1
1 1
2 1
.
1
1
1
1
1
MATHEMATICA
comps[q_]:=Table[Table[Take[q, {Total[Take[c, i-1]]+1, Total[Take[c, i]]}], {i, Length[c]}], {c, Join@@Permutations/@IntegerPartitions[Length[q]]}];
Table[Sum[Length[Select[comps[ptn], And@@SameQ@@@#&&GreaterEqual@@Length/@#&]], {ptn, Sort/@IntegerPartitions[n]}], {n, 10}]
KEYWORD
nonn
AUTHOR
Gus Wiseman, Jan 19 2019
EXTENSIONS
a(21)-a(40) from Seiichi Manyama, Aug 20 2020
STATUS
approved
Number of ways to fill a Young diagram with positive integers summing to n such that all rows and columns are strictly increasing.
+10
3
1, 1, 1, 3, 3, 6, 9, 12, 19, 27, 39, 54, 79, 107, 150, 209, 282, 387, 525, 707, 949, 1272, 1688, 2244, 2968, 3902, 5125, 6712, 8752, 11383, 14780, 19109, 24671, 31768, 40791, 52280, 66860, 85296, 108621, 138054, 175085, 221676, 280161, 353414, 445098, 559661
OFFSET
0,4
COMMENTS
A generalized Young tableau of shape y is an array obtained by replacing the dots in the Ferrers diagram of y with positive integers.
LINKS
The Unapologetic Mathematician weblog, Generalized Young Tableaux.
EXAMPLE
The a(8) = 19 generalized Young tableaux:
8 1 7 2 6 3 5 1 2 5 1 3 4
.
1 2 3 1 2 1 5 1 3 1 4 2 3 1 2 1 2 3
7 6 5 5 2 4 3 3 2 3 2
.
1 1 1 2
2 3 2
5 4 3
MATHEMATICA
primeMS[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];
sqfacs[n_]:=If[n<=1, {{}}, Join@@Table[Map[Prepend[#, d]&, Select[sqfacs[n/d], Min@@#>=d&]], {d, Select[Rest[Divisors[n]], SquareFreeQ]}]];
ptnplane[n_]:=Union[Map[primeMS, Join@@Permutations/@sqfacs[n], {2}]];
Table[Sum[Length[Select[ptnplane[Times@@Prime/@y], And@@(LessEqual@@@Transpose[PadRight[#]/.(0->Infinity)])&&And@@(UnsameQ@@@DeleteCases[Transpose[PadRight[#]], 0, {2}])&]], {y, IntegerPartitions[n]}], {n, 10}]
KEYWORD
nonn
AUTHOR
Gus Wiseman, Jan 16 2019
EXTENSIONS
a(21)-a(45) from Seiichi Manyama, Aug 19 2020
STATUS
approved

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