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 A064333 #12 Sep 08 2022 08:45:04
%S A064333 1,1,-10,221,-6082,187386,-6184848,213843477,-7645509706,280351640702,
%T A064333 -10485617230780,398467433529298,-15341431926699284,
%U A064333 597149747213056324,-23459916801814723548,929028306450848244741,-37045540042729366580442
%N A064333 Generalized Catalan numbers C(-11; n).
%C A064333 See triangle A064334 with columns m built from C(-m; n), m >= 0, also for Derrida et al. references.
%H A064333 G. C. Greubel, <a href="/A064333/b064333.txt">Table of n, a(n) for n = 0..600</a>
%F A064333 a(n) = Sum_{m-0..n-1} (n-m)*binomial(n-1+m, m)*(-11)^m/n.
%F A064333 a(n) = (1/12)^n*(1 + 11*Sum_{k=0..n-1} C(k)*(-11*12)^k ), n >= 1, a(0) := 1; with C(n)=A000108(n) (Catalan).
%F A064333 G.f.: (1+11*x*c(-11*x)/12)/(1-x/12) = 1/(1-x*c(-11*x)) with c(x) g.f. of Catalan numbers A000108.
%t A064333 CoefficientList[Series[(23 +Sqrt[1+44*x])/(2*(12-x)), {x, 0, 30}], x] (* _G. C. Greubel_, May 03 2019 *)
%o A064333 (PARI) my(x='x+O('x^30)); Vec((23 +sqrt(1+44*x))/(2*(12-x))) \\ _G. C. Greubel_, May 03 2019
%o A064333 (Magma) R<x>:=PowerSeriesRing(Rationals(), 30); Coefficients(R!( (23 +Sqrt(1+44*x))/(2*(12-x)) )); // _G. C. Greubel_, May 03 2019
%o A064333 (Sage) ((23 +sqrt(1+44*x))/(2*(12-x))).series(x, 30).coefficients(x, sparse=False) # _G. C. Greubel_, May 03 2019
%Y A064333 Cf. A000108, A064334.
%K A064333 sign,easy
%O A064333 0,3
%A A064333 _Wolfdieter Lang_, Sep 21 2001