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 A286957 #11 Sep 09 2017 07:05:34 %S A286957 1,1,0,1,1,0,1,2,1,0,1,3,2,2,0,1,4,3,6,2,0,1,5,4,12,6,3,0,1,6,5,20,12, %T A286957 10,4,0,1,7,6,30,20,21,18,5,0,1,8,7,42,30,36,48,22,6,0,1,9,8,56,42,55, %U A286957 100,57,30,8,0,1,10,9,72,56,78,180,116,84,42,10,0,1,11,10,90,72,105,294,205,180,120,66,12,0 %N A286957 Square array A(n,k), n>=0, k>=0, read by antidiagonals, where column k is the expansion of Product_{j>=1} (1 + k*x^j). %C A286957 A(n,k) is the number of partitions of n into distinct parts of k sorts: the parts are unordered, but not the sorts. %H A286957 Seiichi Manyama, <a href="/A286957/b286957.txt">Antidiagonals n = 0..139, flattened</a> %H A286957 <a href="/index/Par#part">Index entries for sequences related to partitions</a> %F A286957 G.f. of column k: Product_{j>=1} (1 + k*x^j). %e A286957 Square array begins: %e A286957 1, 1, 1, 1, 1, 1, ... %e A286957 0, 1, 2, 3, 4, 5, ... %e A286957 0, 1, 2, 3, 4, 5, ... %e A286957 0, 2, 6, 12, 20, 30, ... %e A286957 0, 2, 6, 12, 20, 30, ... %e A286957 0, 3, 10, 21, 36, 55, ... %t A286957 Table[Function[k, SeriesCoefficient[Product[(1 + k x^i), {i, 1, Infinity}], {x, 0, n}]][j - n], {j, 0, 12}, {n, 0, j}] // Flatten %t A286957 Table[Function[k, SeriesCoefficient[QPochhammer[-k, x]/(1 + k), {x, 0, n}]][j - n], {j, 0, 12}, {n, 0, j}] // Flatten %Y A286957 Columns k=0-5 give: A000007, A000009, A032302, A032308, A261568, A261569. %Y A286957 Main diagonal gives A291698. %Y A286957 Cf. A246935. %K A286957 nonn,tabl %O A286957 0,8 %A A286957 _Ilya Gutkovskiy_, May 17 2017