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 A290217 #24 Oct 09 2017 00:02:02
%S A290217 1,1,0,1,-1,0,1,-1,0,0,1,-1,-2,-1,0,1,-1,-2,3,1,0,1,-1,-2,0,-1,-1,0,1,
%T A290217 -1,-2,0,5,-5,1,0,1,-1,-2,0,1,1,9,-1,0,1,-1,-2,0,1,9,-12,3,2,0,1,-1,
%U A290217 -2,0,1,4,-4,-3,-20,-2,0,1,-1,-2,0,1,4,6,-15,31,16,2
%N A290217 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/(1 + Sum_{j=1..k} j*x^(j*i)).
%H A290217 Seiichi Manyama, <a href="/A290217/b290217.txt">Antidiagonals n = 0..139, flattened</a>
%e A290217 Square array begins:
%e A290217 1, 1, 1, 1, 1, ...
%e A290217 0, -1, -1, -1, -1, ...
%e A290217 0, 0, -2, -2, -2, ...
%e A290217 0, -1, 3, 0, 0, ...
%e A290217 0, 1, -1, 5, 1, ...
%e A290217 0, -1, -5, 1, 9, ...
%Y A290217 Columns k=0..3 give A000007, A081362, A293287, A290395.
%Y A290217 Rows n=0..1 give A000012, (-1)*A057427.
%Y A290217 Main diagonal gives A258210.
%Y A290217 Cf. A290216, A293307.
%K A290217 sign,tabl
%O A290217 0,13
%A A290217 _Seiichi Manyama_, Oct 06 2017