cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A380959 Array read by antidiagonals downward where A(n,k) is the number of integer partitions of k with product n.

This page as a plain text file.
%I A380959 #11 Feb 11 2025 00:00:02
%S A380959 1,1,0,1,0,0,1,1,0,0,1,1,0,0,0,1,1,1,0,0,0,1,1,1,0,0,0,0,1,1,1,2,0,0,
%T A380959 0,0,1,1,1,2,0,0,0,0,0,1,1,1,2,1,0,0,0,0,0,1,1,1,2,1,1,0,0,0,0,0,1,1,
%U A380959 1,2,1,2,0,0,0,0,0,0
%N A380959 Array read by antidiagonals downward where A(n,k) is the number of integer partitions of k with product n.
%C A380959 Counts finite multisets of positive integers by product and sum.
%F A380959 A(n,k) = A379666(k,n).
%e A380959 Array begins:
%e A380959        k=0 k=1 k=2 k=3 k=4 k=5 k=6 k=7 k=8 k=9 k10 k11 k12
%e A380959        ---------------------------------------------------
%e A380959    n=1: 1   1   1   1   1   1   1   1   1   1   1   1   1
%e A380959    n=2: 0   0   1   1   1   1   1   1   1   1   1   1   1
%e A380959    n=3: 0   0   0   1   1   1   1   1   1   1   1   1   1
%e A380959    n=4: 0   0   0   0   2   2   2   2   2   2   2   2   2
%e A380959    n=5: 0   0   0   0   0   1   1   1   1   1   1   1   1
%e A380959    n=6: 0   0   0   0   0   1   2   2   2   2   2   2   2
%e A380959    n=7: 0   0   0   0   0   0   0   1   1   1   1   1   1
%e A380959    n=8: 0   0   0   0   0   0   2   2   3   3   3   3   3
%e A380959    n=9: 0   0   0   0   0   0   1   1   1   2   2   2   2
%e A380959   n=10: 0   0   0   0   0   0   0   1   1   1   2   2   2
%e A380959   n=11: 0   0   0   0   0   0   0   0   0   0   0   1   1
%e A380959   n=12: 0   0   0   0   0   0   0   2   3   3   3   3   4
%e A380959 The A(12,9) = 3 partitions are: (6,2,1), (4,3,1,1), (3,2,2,1,1).
%e A380959 The A(9,12) = 2 partitions are: (9,1,1,1), (3,3,1,1,1,1,1,1).
%t A380959 nn=12;
%t A380959 tt=Table[Length[Select[IntegerPartitions[k],Times@@#==n&]],{n,1,nn},{k,0,nn}] (* array *)
%t A380959 tr=Table[tt[[j,i-j]],{i,2,nn},{j,i-1}] (* antidiagonals *)
%t A380959 Join@@tr (* sequence *)
%Y A380959 Column sums are A000041 = partitions of n, strict A000009, no ones A002865.
%Y A380959 Diagonal A(n,n) is A001055(n) = factorizations of n, strict A045778.
%Y A380959 Row n converges to A001055(n).
%Y A380959 Lower triangle is A319000.
%Y A380959 Transpose of A379666.
%Y A380959 Antidiagonal sums are A379667, without ones A379669 (zeros A379670), strict A379672.
%Y A380959 A316439 counts factorizations by length, partitions A008284.
%Y A380959 A326622 counts factorizations with integer mean, strict A328966.
%Y A380959 Counting and ranking multisets by comparing sum and product:
%Y A380959 - same: A001055, ranks A301987
%Y A380959 - divisible: A057567, ranks A326155
%Y A380959 - divisor: A057568, ranks A326149, see A379733
%Y A380959 - greater than: A096276 shifted right, ranks A325038
%Y A380959 - greater or equal: A096276, ranks A325044
%Y A380959 - less than: A114324, ranks A325037, see A318029
%Y A380959 - less or equal: A319005, ranks A379721, see A025147
%Y A380959 - different: A379736, ranks A379722, see A111133
%Y A380959 Cf. A003963, A028422, A069016, A319916, A319057, A325036, A325041, A325042, A326152.
%Y A380959 Cf. A318950, A379668, A379671, A379678.
%K A380959 nonn,tabl
%O A380959 0,32
%A A380959 _Gus Wiseman_, Feb 10 2025