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Search: a363626 -id:a363626
Displaying 1-8 of 8 results found. page 1
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A363532 Number of integer partitions of n with weighted alternating sum 0. +10
9
1, 0, 0, 1, 0, 0, 2, 2, 0, 3, 3, 3, 5, 5, 10, 12, 7, 14, 25, 18, 22, 48, 48, 41, 67, 82, 89, 111, 140, 170, 220, 214, 264, 392, 386, 436, 623, 693, 756, 934, 1102, 1301, 1565, 1697, 2132, 2616, 2727, 3192, 4062, 4550, 5000, 6132, 7197, 8067, 9338, 10750, 12683 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,7
COMMENTS
We define the weighted alternating sum of a sequence (y_1,...,y_k) to be Sum_{i=1..k} (-1)^(i-1) * i * y_i.
LINKS
Table of n, a(n) for n=0..56.
EXAMPLE
The a(11) = 3 through a(15) = 12 partitions (A = 10):
(33221) (84) (751) (662) (A5)
(44111) (6222) (5332) (4442) (8322)
(222221) (7311) (6421) (5531) (9411)
(621111) (532111) (43331) (722211)
(51111111) (42211111) (54221) (831111)
(65111) (3322221)
(432221) (3333111)
(443111) (4422111)
(32222111) (5511111)
(33311111) (22222221)
(72111111)
(6111111111)
MATHEMATICA
altwtsum[y_]:=Sum[(-1)^(k-1)*k*y[[k]], {k, 1, Length[y]}];
Table[Length[Select[IntegerPartitions[n], altwtsum[#]==0&]], {n, 0, 30}]
CROSSREFS
The unweighted version is A035363.
These partitions have ranks A363621.
The triangle for this rank statistic is A363623, reverse A363622.
The version for compositions is A363626.
A000041 counts integer partitions.
A264034 counts partitions by weighted sum, reverse A358194.
A304818 gives weighted sum of prime indices, reverse A318283.
A316524 gives alternating sum of prime indices, reverse A344616.
A363619 gives weighted alternating sum of prime indices, reverse A363620.
A363624 gives weighted alternating sum of Heinz partition, reverse A363625.
Cf. A008284, A053632, A106529, A261079, A320387, A360672, A360675, A362559.
KEYWORD
nonn
AUTHOR
Gus Wiseman, Jun 14 2023
STATUS
approved
A222970 Number of 1 X (n+1) 0..1 arrays with every row least squares fitting to a positive-slope straight line and every column least squares fitting to a zero- or positive-slope straight line, with a single point array taken as having zero slope. +10
8
1, 2, 6, 12, 28, 54, 119, 230, 488, 948, 1979, 3860, 7978, 15624, 32072, 63014, 128746, 253588, 516346, 1019072, 2069590, 4091174, 8291746, 16412668, 33210428, 65808044, 132985161, 263755984, 532421062, 1056789662, 2131312530, 4233176854 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
From Gus Wiseman, Jun 16 2023: (Start)
Also appears to be the number of integer compositions of n + 2 with weighted sum greater than reverse-weighted sum, where the weighted sum of a sequence (y_1,...,y_k) is Sum_{i=1..k} i * y_i, and the reverse is Sum_{i=1..k} i * y_{k-i+1}. The a(1) = 1 through a(4) = 12 compositions are:
(21) (31) (32) (42)
(211) (41) (51)
(221) (231)
(311) (312)
(1211) (321)
(2111) (411)
(1311)
(2121)
(2211)
(3111)
(12111)
(21111)
The version for partitions is A144300, strict A111133.
(End)
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
EXAMPLE
Some solutions for n=3:
0 1 0 1 0 1 1 1 0 0 1 0 0 0 1 1 0 0 0 1
CROSSREFS
For >= instead of > we have A222855.
The case of equality is A222955.
Row 1 of A222969.
A053632 counts compositions by weighted sum (or reverse-weighted sum).
A264034 counts partitions by weighted sum, reverse A358194.
A304818 gives weighted sum of prime indices, reverse A318283.
Cf. A000005, A000041, A138364, A320387, A360672, A360675, A363626.
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 10 2013
STATUS
approved
A363619 Weighted alternating sum of the multiset of prime indices of n. +10
8
0, 1, 2, -1, 3, -3, 4, 2, -2, -5, 5, 5, 6, -7, -4, -2, 7, 3, 8, 8, -6, -9, 9, -6, -3, -11, 4, 11, 10, 6, 11, 3, -8, -13, -5, -3, 12, -15, -10, -10, 13, 9, 14, 14, 7, -17, 15, 8, -4, 4, -12, 17, 16, -5, -7, -14, -14, -19, 17, -7, 18, -21, 10, -3, -9, 12, 19, 20 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
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.
We define the weighted alternating sum of a sequence (y_1,...,y_k) to be Sum_{i=1..k} (-1)^(i-1) i * y_i.
LINKS
Table of n, a(n) for n=1..68.
EXAMPLE
The prime indices of 300 are {1,1,2,3,3}, with weighted alternating sum 1*1 - 2*1 + 3*2 - 4*3 + 5*3 = 8, so a(300) = 8.
MATHEMATICA
prix[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];
altwtsum[y_]:=Sum[(-1)^(k-1)*k*y[[k]], {k, 1, Length[y]}];
Table[altwtsum[prix[n]], {n, 100}]
CROSSREFS
The non-alternating version is A304818, reverse A318283.
The unweighted version is A316524, reverse A344616.
The reverse version is A363620.
The triangle for this rank statistic is A363622, reverse A363623.
For partitions instead of multisets we have A363624, reverse A363625.
A055396 gives minimum prime index, maximum A061395.
A112798 lists prime indices, length A001222, sum A056239.
A264034 counts partitions by weighted sum, reverse A358194.
A320387 counts multisets by weighted sum, zero-based A359678.
A359677 gives zero-based weighted sum of prime indices, reverse A359674.
Cf. A000009, A000720, A001221, A046660, A053632, A106529, A124010, A181819, A261079, A363532, A363621, A363626.
KEYWORD
sign
AUTHOR
Gus Wiseman, Jun 12 2023
STATUS
approved
A363621 Positive integers whose prime indices have reverse-weighted alternating sum 0. +10
8
1, 6, 21, 40, 50, 54, 65, 132, 133, 154, 210, 224, 319, 340, 351, 360, 374, 392, 450, 481, 486, 507, 546, 598, 624, 644, 731, 825, 855, 969, 1007, 1029, 1054, 1144, 1210, 1254, 1320, 1364, 1386, 1403, 1408, 1520, 1558, 1653, 1750, 1785, 1827, 1836, 1890, 1960 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
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.
We define the reverse-weighted alternating sum of a sequence (y_1,...,y_k) to be Sum_{i=1..k} (-1)^(k-i) i * y_{k-i+1}.
LINKS
Table of n, a(n) for n=1..50.
EXAMPLE
The prime indices of 360 are {1,1,1,2,2,3}, with reverse-weighted alternating sum 1*3 - 2*2 + 3*2 - 4*1 + 5*1 - 6*1 = 0, so 360 is in the sequence.
The terms together with their prime indices begin:
1: {}
6: {1,2}
21: {2,4}
40: {1,1,1,3}
50: {1,3,3}
54: {1,2,2,2}
65: {3,6}
132: {1,1,2,5}
133: {4,8}
154: {1,4,5}
210: {1,2,3,4}
224: {1,1,1,1,1,4}
319: {5,10}
340: {1,1,3,7}
351: {2,2,2,6}
360: {1,1,1,2,2,3}
MATHEMATICA
prix[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];
revaltwtsum[y_]:=Sum[(-1)^(Length[y]-k)*k*y[[-k]], {k, 1, Length[y]}];
Select[Range[1000], revaltwtsum[prix[#]]==0&]
CROSSREFS
The unweighted version is A000290.
Partitions of this type are counted by A363532.
Positions of zeros in A363620 and A363624, reverse A363619 and A363625.
Compositions of this type are counted by A363626.
A053632 counts compositions by weighted sum.
A055396 gives minimum prime index, maximum A061395.
A112798 lists prime indices, length A001222, sum A056239.
A264034 counts partitions by weighted sum, reverse A358194.
A304818 gives weighted sum of prime indices.
A318283 gives weighted sum of reversed prime indices.
A320387 counts multisets by weighted sum.
A344616 gives reverse-alternating sum of prime indices.
A363623 counts partitions by reverse-weighted alternating sum.
Cf. A046660, A106529, A124010, A181819, A261079, A316524, A359674, A363622.
KEYWORD
nonn
AUTHOR
Gus Wiseman, Jun 13 2023
STATUS
approved
A363622 Irregular triangle read by rows where T(n,k) is the number of integer partitions of n with weighted alternating sum k (leading and trailing 0's omitted). +10
8
1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 2, 0, 0, 1, 0, 1, 1, 2, 0, 1, 1, 1, 1, 1, 3, 0, 0, 2, 0, 1, 1, 2, 1, 1, 3, 0, 2, 2, 1, 1, 2, 2, 1, 1, 5, 0, 0, 3, 0, 2, 2, 2, 1, 3, 2, 1, 1, 5, 0, 3, 3, 2, 2, 3, 2, 2, 4, 2, 1, 1, 7, 0, 0, 5, 0, 3, 3, 4, 2, 4, 2, 4, 4, 2, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,11
COMMENTS
We define the weighted alternating sum of a sequence (y_1,...,y_k) to be Sum_{i=1..k} (-1)^(i-1) i * y_i. For example:
- (3,3,2,1,1) has weighted alternating sum 1*3 - 2*3 + 3*2 - 4*1 + 5*1 = 4.
- (1,2,2,3) has weighted alternating sum 1*1 - 2*2 + 3*2 - 4*3 = -9.
LINKS
Table of n, a(n) for n=0..85.
EXAMPLE
Triangle begins:
1
1
1 0 0 1
1 0 1 1
2 0 0 1 0 1 1
2 0 1 1 1 1 1
3 0 0 2 0 1 1 2 1 1
3 0 2 2 1 1 2 2 1 1
5 0 0 3 0 2 2 2 1 3 2 1 1
5 0 3 3 2 2 3 2 2 4 2 1 1
7 0 0 5 0 3 3 4 2 4 2 4 4 2 1 1
7 0 5 5 3 3 5 4 3 5 3 5 4 2 1 1
Row n = 6 counts the following partitions:
k=-3 k=0 k=2 k=3 k=4 k=5 k=6
-----------------------------------------------------------
(33) . . (42) . (321) (51) (222) (411) (6)
(2211) (3111) (21111)
(111111)
MATHEMATICA
altwtsum[y_]:=Sum[(-1)^(k-1)*k*y[[k]], {k, 1, Length[y]}];
Table[Length[Select[IntegerPartitions[n], altwtsum[#]==k&]], {n, 0, 15}, {k, Min[altwtsum/@IntegerPartitions[n]], Max[altwtsum/@IntegerPartitions[n]]}]
CROSSREFS
Row sums are A000041.
The unweighted version is A103919 with leading zeros removed.
Row-lengths appear to be A168233.
Central column T(n,0) is A363532, ranks A363621.
The corresponding rank statistic is A363619, reverse A363620.
The reverse version is A363623.
A053632 counts compositions by weighted sum.
A264034 counts partitions by weighted sum, reverse A358194.
A316524 gives alternating sum of prime indices, reverse A344616.
A363624 gives weighted alternating sum of Heinz partition, reverse A363625.
Cf. A008284, A067538, A222855, A222970, A318283, A320387, A360672, A360675, A362559, A363626.
KEYWORD
nonn,tabf
AUTHOR
Gus Wiseman, Jun 15 2023
STATUS
approved
A363623 Irregular triangle read by rows where T(n,k) is the number of integer partitions of n with reverse-weighted alternating sum k (leading and trailing 0's omitted). +10
8
1, 1, 1, 1, 1, 2, 2, 0, 1, 2, 2, 1, 1, 1, 1, 1, 3, 1, 0, 3, 0, 1, 1, 1, 1, 3, 2, 0, 3, 1, 2, 0, 1, 0, 1, 2, 5, 1, 0, 3, 1, 2, 2, 2, 1, 1, 0, 1, 0, 1, 2, 5, 3, 0, 4, 2, 2, 0, 3, 2, 1, 3, 0, 0, 1, 0, 1, 1, 1, 1, 7, 2, 0, 4, 1, 5, 2, 3, 1, 3, 0, 2, 3, 1, 2, 1, 0, 0, 1, 0, 1, 1, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,6
COMMENTS
We define the reverse-weighted alternating sum of a sequence (y_1,...,y_k) to be Sum_{i=1..k} (-1)^(k-i) i * y_{k-i+1}. For example:
- (3,3,2,1,1) has reverse-weighted alternating sum 1*1 - 2*1 + 3*2 - 4*3 + 5*3 = 8.
- (1,2,2,3) has reverse-weighted alternating sum -1*3 + 2*2 - 3*2 + 4*1 = -1.
LINKS
Table of n, a(n) for n=0..93.
EXAMPLE
Triangle begins:
1
1
1 1
1 2
2 0 1 2
2 1 1 1 1 1
3 1 0 3 0 1 1 1 1
3 2 0 3 1 2 0 1 0 1 2
5 1 0 3 1 2 2 2 1 1 0 1 0 1 2
5 3 0 4 2 2 0 3 2 1 3 0 0 1 0 1 1 1 1
Row n = 6 counts the following partitions:
k=3 k=4 k=6 k=8 k=9 k=10 k=11
--------------------------------------------------------------
(33) (222) . (6) . (21111) (51) (3111) (411)
(2211) (42)
(111111) (321)
MATHEMATICA
revaltwtsum[y_]:=Sum[(-1)^(Length[y]-k)*k*y[[-k]], {k, 1, Length[y]}];
Table[Length[Select[IntegerPartitions[n], revaltwtsum[#]==k&]], {n, 0, 15}, {k, Floor[(n+1)/2], Ceiling[n*(n+1)/4]}]
CROSSREFS
Row sums are A000041.
Column k = floor((n+1)/2) is A119620.
The unweighted version is A344612 aerated, reverse A103919.
The corresponding rank statistic is A363620, reverse A363619.
The reverse version is A363622.
A053632 counts compositions by weighted sum.
A264034 counts partitions by weighted sum, reverse A358194.
A316524 gives alternating sum of prime indices, reverse A344616.
A363624 gives weighted alternating sum of Heinz partition, reverse A363625.
Cf. A008284, A067538, A222855, A222970, A318283, A320387, A360672, A360675, A362559, A363532, A363621, A363626.
KEYWORD
nonn,tabf
AUTHOR
Gus Wiseman, Jun 15 2023
STATUS
approved
A363624 Weighted alternating sum of the integer partition with Heinz number n. +10
8
0, 1, 2, -1, 3, 0, 4, 2, -2, 1, 5, 3, 6, 2, -1, -2, 7, 1, 8, 4, 0, 3, 9, -1, -3, 4, 4, 5, 10, 2, 11, 3, 1, 5, -2, -3, 12, 6, 2, 0, 13, 3, 14, 6, 5, 7, 15, 4, -4, 0, 3, 7, 16, 0, -1, 1, 4, 8, 17, -2, 18, 9, 6, -3, 0, 4, 19, 8, 5, 1, 20, 2, 21, 10, 3, 9, -3, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
The Heinz number of a partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k). This gives a bijective correspondence between positive integers and integer partitions.
We define the weighted alternating sum of a sequence (y_1,...,y_k) to be Sum_{i=1..k} (-1)^(i - 1) * i * y_i.
LINKS
Table of n, a(n) for n=1..78.
EXAMPLE
The partition with Heinz number 600 is (3,3,2,1,1,1), with weighted alternating sum 1*3 - 2*3 + 3*2 - 4*1 + 5*1 - 6*1 = -2, so a(600) = -2.
MATHEMATICA
prix[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];
altwtsum[y_]:=Sum[(-1)^(k-1)*k*y[[k]], {k, 1, Length[y]}];
Table[altwtsum[Reverse[prix[n]]], {n, 100}]
CROSSREFS
The non-alternating version is A318283, reverse A304818.
The unweighted version is A344616, reverse A316524.
For multisets instead of partitions we have A363619.
Positions of zeros are A363621, counted by A363532.
The triangle for this rank statistic is A363622, reverse A363623.
The reverse version is A363625, for multisets A363620.
A055396 gives minimum prime index, maximum A061395.
A112798 lists prime indices, length A001222, sum A056239.
A264034 counts partitions by weighted sum, reverse A358194.
A320387 counts multisets by weighted sum, reverse A007294.
A359677 gives zero-based weighted sum of prime indices, reverse A359674.
A363626 counts compositions with reverse-weighted alternating sum 0.
Cf. A046660, A053632, A106529, A124010, A215366, A261079, A358136, A359361, A359755.
KEYWORD
sign
AUTHOR
Gus Wiseman, Jun 13 2023
STATUS
approved
A363625 Reverse-weighted alternating sum of the integer partition with Heinz number n. +10
8
0, 1, 2, 1, 3, 3, 4, 2, 2, 5, 5, 5, 6, 7, 4, 2, 7, 3, 8, 8, 6, 9, 9, 6, 3, 11, 4, 11, 10, 6, 11, 3, 8, 13, 5, 3, 12, 15, 10, 10, 13, 9, 14, 14, 7, 17, 15, 8, 4, 4, 12, 17, 16, 5, 7, 14, 14, 19, 17, 7, 18, 21, 10, 3, 9, 12, 19, 20, 16, 7, 20, 4, 21, 23, 5, 23 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
The Heinz number of a partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k). This gives a bijective correspondence between positive integers and integer partitions.
We define the reverse-weighted alternating sum of a sequence (y_1,...,y_k) to be Sum_{i=1..k} (-1)^(k-i) * i * y_{k-i+1}.
LINKS
Table of n, a(n) for n=1..76.
EXAMPLE
The partition with Heinz number 600 is (3,3,2,1,1,1), so a(600) = -1*1 + 2*1 - 3*1 + 4*2 - 5*3 + 6*3 = 9.
MATHEMATICA
prix[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];
revaltwtsum[y_]:=Sum[(-1)^(Length[y]-k)*k*y[[-k]], {k, 1, Length[y]}];
Table[revaltwtsum[Reverse[prix[n]]], {n, 100}]
CROSSREFS
The non-alternating version is A304818, reverse A318283.
The unweighted version is A316524, reverse A344616.
For multisets instead of partitions we have A363620.
The triangle for this rank statistic is A363623, reverse A363622.
The reverse version is A363624, for multisets A363619.
A055396 gives minimum prime index, maximum A061395.
A112798 lists prime indices, length A001222, sum A056239.
A264034 counts partitions by weighted sum, reverse A358194.
A320387 counts multisets by weighted sum, reverse A007294.
Cf. A046660, A053632, A106529, A124010, A261079, A359361, A359755, A363532, A363621, A363626.
KEYWORD
nonn
AUTHOR
Gus Wiseman, Jun 15 2023
STATUS
approved
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