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 A376134 #7 Oct 05 2024 18:05:53
%S A376134 1,1,-1,-6,17,141,-660,-6688,43837,521755,-4412893,-60477282,
%T A376134 628119268,9772644140,-120524236108,-2103803950976,30068650440341,
%U A376134 582807287964375,-9477098158324107,-202143447363632090,3686281848172281145,85853256990102196221,-1735552985238117874788
%N A376134 a(0) = 1; a(n) = Sum_{k=0..n-1} (-1)^k * (k+1) * a(k) * a(n-k-1).
%F A376134 G.f. A(x) satisfies: A(x) = 1 / (1 - x * A(-x) + x^2 * A'(-x)).
%t A376134 a[0] = 1; a[n_] := a[n] = Sum[(-1)^k (k + 1) a[k] a[n - k - 1], {k, 0, n - 1}]; Table[a[n], {n, 0, 22}]
%t A376134 nmax = 22; A[_] = 0; Do[A[x_] = 1/(1 - x A[-x] + x^2 A'[-x]) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
%Y A376134 Cf. A088716, A090192, A105523, A376135, A376137.
%K A376134 sign
%O A376134 0,4
%A A376134 _Ilya Gutkovskiy_, Sep 11 2024