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 A377633 #9 Nov 03 2024 09:31:49
%S A377633 1,2,22,474,15512,685450,38251212,2582466950,204744089104,
%T A377633 18650699228754,1919767092675860,220378941471652942,
%U A377633 27916112634179586456,3868191824049865945178,582034397153512353488284,94509039130326185624148150,16472375319790734221438146592,3067435511995844132675459958178
%N A377633 E.g.f. satisfies A(x) = (1 + x * A(x)^2 * exp(x*A(x)^2))^2.
%F A377633 E.g.f.: B(x)^2, where B(x) is the e.g.f. of A364989.
%F A377633 a(n) = (n!/(2*n+1)) * Sum_{k=0..n} k^(n-k) * binomial(4*n+2,k)/(n-k)!.
%o A377633 (PARI) a(n) = n!*sum(k=0, n, k^(n-k)*binomial(4*n+2, k)/(n-k)!)/(2*n+1);
%Y A377633 Cf. A364989, A377630.
%K A377633 nonn
%O A377633 0,2
%A A377633 _Seiichi Manyama_, Nov 02 2024