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 A003236 M3107 #33 Dec 26 2021 20:41:30
%S A003236 1,3,24,320,6122,153762,4794664,178788528,7762727196,384733667780,
%T A003236 21434922419504,1326212860090560,90227121642144424,
%U A003236 6694736236093168200,538028902298395832832,46558260925421295229568,4316186393637505403773328
%N A003236 a(n) = Sum_{k=0..n} (-1)^(n-k) C(n,k)*C((k+1)^2, n).
%D A003236 H. W. Gould, personal communication.
%D A003236 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A003236 Alois P. Heinz, <a href="/A003236/b003236.txt">Table of n, a(n) for n = 0..300</a>
%H A003236 Henry W. Gould, <a href="/A003099/a003099.pdf">Letters to N. J. A. Sloane, Oct 1973 and Jan 1974</a>.
%F A003236 a(n) ~ c * d^n * (n-1)!, where d = 4 / (w*(2-w)) = 6.17655460948348035823168... and c = exp(1/2 - w^2/8) / (Pi*sqrt(2*w*(1-w))) = 0.740112385268663459927202070799244309431121698475089032623558890186368006364..., where w = -LambertW(-2*exp(-2)) = -A226775. - _Vaclav Kotesovec_, Dec 13 2020, updated Jul 09 2021
%F A003236 a(n) / A003235(n) ~ -2 / LambertW(-2*exp(-2)) = 4.92155363456750509... - _Vaclav Kotesovec_, Jul 09 2021
%t A003236 Table[Sum[(-1)^(n-k) * Binomial[n,k] * Binomial[(k+1)^2, n], {k,0,n}], {n,0,20}] (* _Vaclav Kotesovec_, Dec 13 2020 *)
%Y A003236 Cf. A346183.
%K A003236 nonn
%O A003236 0,2
%A A003236 _N. J. A. Sloane_
%E A003236 More terms from _Sean A. Irvine_, Mar 19 2015