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 A347080 #8 Jan 27 2022 20:55:54 %S A347080 0,1,-1,-2,2,13,-16,-161,170,2647,-1711,-51248,5711,1103710,599246, %T A347080 -25521869,-33907174,620323849,1410745127,-15678980390,-53746958146, %U A347080 411344661913,1998823108706,-11256049308869,-75003366373495,323285264486686,2904292324907387 %N A347080 G.f. A(x) satisfies: A(x) = x + x * A(A(-x)). %t A347080 nmax = 26; A[_] = 0; Do[A[x_] = x + x A[A[-x]] + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x] %Y A347080 Cf. A030266, A030277, A171212. %K A347080 sign %O A347080 0,4 %A A347080 _Ilya Gutkovskiy_, Jan 27 2022