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 A291207 #12 Sep 29 2017 11:24:12
%S A291207 1,1,-1,1,-1,0,1,-1,-1,1,1,-1,-3,5,0,1,-1,-7,27,17,-2,1,-1,-15,167,
%T A291207 441,-121,0,1,-1,-31,1071,10673,-11529,-721,5,1,-1,-63,6815,262305,
%U A291207 -1337713,-442827,6845,0,1,-1,-127,42687,6525377,-161721441,-297209047,23444883,58337,-14
%N A291207 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of continued fraction 1/(1 + x/(1 - 2^k*x/(1 + 3^k*x/(1 - 4^k*x/(1 + 5^k*x/(1 - ...)))))).
%F A291207 G.f. of column k: 1/(1 + x/(1 - 2^k*x/(1 + 3^k*x/(1 - 4^k*x/(1 + 5^k*x/(1 - ...)))))), a continued fraction.
%e A291207 G.f. of column k: A_k(x) = 1 - x + (1 - 2^k)*x^2 + (2^(k + 1) - 4^k + 6^k - 1)*x^3 + ...
%e A291207 Square array begins:
%e A291207 1, 1, 1, 1, 1, 1, ...
%e A291207 -1, -1, -1, -1, -1, -1, ...
%e A291207 0, -1, -3, -7, -15, -31, ...
%e A291207 1, 5, 27, 167, 1071, 6815, ...
%e A291207 0, 17, 441, 10673, 262305, 6525377, ...
%e A291207 -2, -121, -11529, -1337713, -161721441, -19802585281, ...
%t A291207 Table[Function[k, SeriesCoefficient[1/(1 + ContinuedFractionK[-(-1)^i i^k x, 1, {i, 1, n}]), {x, 0, n}]][j - n], {j, 0, 9}, {n, 0, j}] // Flatten
%Y A291207 Columns k=0-2 give A105523, A202038, A193544.
%Y A291207 Main diagonal gives A292920.
%Y A291207 Cf. A290569.
%K A291207 sign,tabl
%O A291207 0,13
%A A291207 _Ilya Gutkovskiy_, Aug 21 2017