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 A294808 #21 Nov 18 2017 04:21:39 %S A294808 1,1,-1,1,-1,-2,1,-1,-8,-1,1,-1,-32,-73,0,1,-1,-128,-2155,-927,4,1,-1, %T A294808 -512,-58921,-259701,-13969,4,1,-1,-2048,-1593811,-67045719,-48496253, %U A294808 -254580,7,1,-1,-8192,-43044673,-17178209325,-152513227585,-13001952944,-5288596,3 %N A294808 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of Product_{j>=1} (1-j^(k*j)*x^j)^j in powers of x. %H A294808 Seiichi Manyama, <a href="/A294808/b294808.txt">Antidiagonals n = 0..52, flattened</a> %F A294808 A(0,k) = 1 and A(n,k) = -(1/n) * Sum_{j=1..n} (Sum_{d|j} d^(2+k*j)) * A(n-j,k) for n > 0. %e A294808 Square array begins: %e A294808 1, 1, 1, 1, 1, ... %e A294808 -1, -1, -1, -1, -1, ... %e A294808 -2, -8, -32, -128, -512, ... %e A294808 -1, -73, -2155, -58921, -1593811, ... %e A294808 0, -927, -259701, -67045719, -17178209325, ... %e A294808 4, -13969, -48496253, -152513227585, -476819162106101, ... %Y A294808 Columns k=0..2 give A073592, A294809, A294953. %Y A294808 Rows n=0..2 give A000012, (-1)*A000012, (-1)*A004171. %Y A294808 Cf. A294653, A294950. %K A294808 sign,tabl %O A294808 0,6 %A A294808 _Seiichi Manyama_, Nov 09 2017