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.
%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