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 A319753 #10 Dec 06 2020 06:27:14 %S A319753 1,1,-1,1,0,-1,1,1,0,0,1,2,3,0,0,1,3,8,6,0,1,1,4,15,24,14,0,0,1,5,24, %T A319753 60,78,27,0,1,1,6,35,120,252,232,60,0,0,1,7,48,210,620,1005,720,117,0, %U A319753 0,1,8,63,336,1290,3096,4080,2152,246,0,0,1,9,80,504,2394,7735,15600,16305,6528,490,0,0 %N A319753 Square array A(n,k), n>=0, k>=0, read by antidiagonals, where column k is the expansion of Product_{j>=1} (1 - x^j)/(1 - k*x^j). %H A319753 Seiichi Manyama, <a href="/A319753/b319753.txt">Antidiagonals n = 0..139, flattened</a> %F A319753 G.f. of column k: Product_{j>=1} (1 - x^j)/(1 - k*x^j). %F A319753 G.f. of column k: exp(Sum_{j>=1} ( Sum_{d|j} d*(k^(j/d) - 1) ) * x^j/j). %e A319753 Square array begins: %e A319753 1, 1, 1, 1, 1, 1, ... %e A319753 -1, 0, 1, 2, 3, 4, ... %e A319753 -1, 0, 3, 8, 15, 24, ... %e A319753 0, 0, 6, 24, 60, 120, ... %e A319753 0, 0, 14, 78, 252, 620, ... %e A319753 1, 0, 27, 232, 1005, 3096, ... %t A319753 Table[Function[k, SeriesCoefficient[Product[(1 - x^i)/(1 - k x^i), {i, n}], {x, 0, n}]][j - n], {j, 0, 11}, {n, 0, j}] // Flatten %t A319753 Table[Function[k, SeriesCoefficient[Exp[Sum[Sum[d (k^(i/d) - 1), {d, Divisors[i]}] x^i/i, {i, n}]], {x, 0, n}]][j - n], {j, 0, 11}, {n, 0, j}] // Flatten %Y A319753 Columns k=0..20 give A010815, A000007, A006951, A006952, A049314, A049315, A221578, A049316, A182603, A182604, A221579, A182605, A221580, A182606, A221581, A221582, A182607, A182608, A221583, A182609, A221584. %Y A319753 Main diagonal gives A319754. %K A319753 sign,tabl %O A319753 0,12 %A A319753 _Ilya Gutkovskiy_, Sep 27 2018