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 A294951 #14 Nov 13 2017 13:27:11 %S A294951 1,1,-1,1,-1,-3,1,-1,-5,-1,1,-1,-9,-7,1,1,-1,-17,-31,1,279,1,-1,-33, %T A294951 -115,-23,839,301,1,-1,-65,-391,-215,3399,4171,12263,1,-1,-129,-1267, %U A294951 -1319,17519,41311,54305,5601,1,-1,-257,-3991,-6839,102999,387031,473129,102817,-431281 %N A294951 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f.: exp(-Sum_{j>=1} sigma_k(j) * x^j). %F A294951 A(0,k) = 1 and A(n,k) = -(n-1)! * Sum_{j=1..n} j*sigma_k(j)*A(n-j,k)/(n-j)! for n > 0. %e A294951 Square array A(n,k) begins: %e A294951 1, 1, 1, 1, 1, ... %e A294951 -1, -1, -1, -1, -1, ... %e A294951 -3, -5, -9, -17, -33, ... %e A294951 -1, -7, -31, -115, -391, ... %e A294951 1, 1, -23, -215, -1319, ... %e A294951 279, 839, 3399, 17519, 102999, ... %Y A294951 Columns k=0..2 give A294402, A294403, A294404. %Y A294951 Rows n=0..2 give A000012, (-1)*A000012, (-1)*A000051(n+1). %Y A294951 Cf. A294947. %K A294951 sign,tabl %O A294951 0,6 %A A294951 _Seiichi Manyama_, Nov 12 2017