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 A293388 #17 Oct 09 2017 10:15:16
%S A293388 1,1,0,1,-2,0,1,-2,-1,0,1,-2,3,2,0,1,-2,3,-2,1,0,1,-2,3,-8,1,2,0,1,-2,
%T A293388 3,-8,7,-6,-2,0,1,-2,3,-8,15,-6,14,0,0,1,-2,3,-8,15,-14,17,-20,-2,0,1,
%U A293388 -2,3,-8,15,-24,17,-14,22,-2,0,1,-2,3,-8,15,-24,27
%N A293388 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of g.f. Product_{i>0} (1 + Sum_{j=1..k} (-1)^j*j*x^(j*i))^2.
%H A293388 Seiichi Manyama, <a href="/A293388/b293388.txt">Antidiagonals n = 0..139, flattened</a>
%e A293388 Square array begins:
%e A293388 1, 1, 1, 1, 1, ...
%e A293388 0, -2, -2, -2, -2, ...
%e A293388 0, -1, 3, 3, 3, ...
%e A293388 0, 2, -2, -8, -8, ...
%e A293388 0, 1, 1, 7, 15, ...
%e A293388 0, 2, -6, -6, -14, ...
%Y A293388 Columns k=0..1 give A000007, A002107.
%Y A293388 Rows n=0 gives A000012.
%Y A293388 Main diagonal gives A293389.
%Y A293388 Product_{i>0} 1/(1 + Sum_{j=1..k} (-1)^j*j*x^(j*i))^m: A292577 (m=-2), A293307 (m=-1), A293305 (m=1), this sequence (m=2).
%K A293388 sign,tabl
%O A293388 0,5
%A A293388 _Seiichi Manyama_, Oct 07 2017