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 A293299 #17 Oct 05 2017 11:22:13 %S A293299 1,1,0,1,-1,0,1,-1,0,0,1,-1,-1,-6,0,1,-1,-1,0,24,0,1,-1,-1,-1,-6,-120, %T A293299 0,1,-1,-1,-1,2,30,720,0,1,-1,-1,-1,1,10,270,-5040,0,1,-1,-1,-1,1,20, %U A293299 170,0,80640,0,1,-1,-1,-1,1,19,140,1050,2520,-725760,0,1,-1 %N A293299 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f. Product_{i>0} 1/(Sum_{j=0..k} x^(j*i)/j!). %H A293299 Seiichi Manyama, <a href="/A293299/b293299.txt">Antidiagonals n = 0..139, flattened</a> %e A293299 Square array begins: %e A293299 1, 1, 1, 1, 1, ... %e A293299 0, -1, -1, -1, -1, ... %e A293299 0, 0, -1, -1, -1, ... %e A293299 0, -6, 0, -1, -1, ... %e A293299 0, 24, -6, 2, 1, ... %e A293299 0, -120, 30, 10, 20, ... %Y A293299 Columns k=0..1 give A000007, A293300. %Y A293299 Rows n=0 gives A000012. %Y A293299 Main diagonal gives A293116. %Y A293299 Cf. A293135, A293301. %K A293299 sign,tabl %O A293299 0,14 %A A293299 _Seiichi Manyama_, Oct 05 2017