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 A137610 #5 Aug 20 2025 07:39:35
%S A137610 1,2,13,180,3844,110908,4030740,176640072,9059743648,532179428700,
%T A137610 35219852623888,2592514449263656,210072673380786552,
%U A137610 18579938909696752728,1780987027765227959096,183907984490301947455872
%N A137610 Self-convolution of A014062, where A014062(n) = C(n^2, n).
%F A137610 a(n) = Sum_{k=0..n} C(k^2, k) * C((n-k)^2, n-k).
%F A137610 a(n) ~ sqrt(2) * exp(n - 1/2) * n^(n - 1/2) / sqrt(Pi). - _Vaclav Kotesovec_, Aug 20 2025
%t A137610 Table[Sum[Binomial[k^2, k]*Binomial[(n-k)^2, n-k], {k,0,n}], {n,0,20}] (* _Vaclav Kotesovec_, Aug 20 2025 *)
%o A137610 (PARI) a(n)=sum(k=0,n,binomial(k^2,k)*binomial((n-k)^2,n-k))
%Y A137610 Cf. A014062.
%K A137610 nonn
%O A137610 0,2
%A A137610 _Paul D. Hanna_, Jan 29 2008