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 A294947 #13 Nov 13 2017 13:26:50 %S A294947 1,1,-1,1,-1,-2,1,-1,-4,-7,1,-1,-8,-23,-57,1,-1,-16,-73,-229,-541,1, %T A294947 -1,-32,-227,-927,-2761,-7126,1,-1,-64,-697,-3757,-13969,-42615, %U A294947 -108072,1,-1,-128,-2123,-15207,-70237,-254580,-758499,-1966034 %N A294947 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of exp(-Sum_{j>0} sigma_k(j)*x^j/j) in powers of x. %F A294947 G.f. of column k: Product_{j>0} (1 - j^j*x^j)^(j^(k-1)). %e A294947 Square array begins: %e A294947 1, 1, 1, 1, 1, ... %e A294947 -1, -1, -1, -1, -1, ... %e A294947 -2, -4, -8, -16, -32, ... %e A294947 -7, -23, -73, -227, -697, ... %e A294947 -57, -229, -927, -3757, -15207, ... %e A294947 -541, -2761, -13969, -70237, -351361, ... %Y A294947 Columns k=0..2 give A294948, A292312, A294809. %Y A294947 Rows n=0..1 give A000012, (-1)*A000012. %Y A294947 Cf. A294946, A294951. %K A294947 sign,tabl %O A294947 0,6 %A A294947 _Seiichi Manyama_, Nov 11 2017