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 A372251 #12 Apr 24 2024 08:20:42
%S A372251 1,1,6,73,1364,34586,1110496,43207004,1976199792,103925934712,
%T A372251 6178846168976,409847155094840,30007066358487040,2403751529017358144,
%U A372251 209131503815967330816,19637892118783264231936,1979605910448187576510208,213226210180592877512104832
%N A372251 E.g.f. A(x) satisfies A(x) = exp( x * A(x)^2 * (1 + A(x))/2 ).
%F A372251 a(n) = 1/2 * Sum_{k=0..n} (n+k/2+1/2)^(n-1) * binomial(n,k).
%F A372251 a(n) ~ sqrt((1 + s)/(4 + 9*s)) * s^(2*n + 1) * (2 + 3*s)^n * n^(n-1) / (2^n * exp(n)), where s = 1.470103625022272111740158699814771551850270522048... is the root of the equation log(s) = (1 + s)/(2 + 3*s). - _Vaclav Kotesovec_, Apr 24 2024
%o A372251 (PARI) a(n) = sum(k=0, n, (n+k/2+1/2)^(n-1)*binomial(n, k))/2;
%Y A372251 Cf. A138860, A372246.
%K A372251 nonn
%O A372251 0,3
%A A372251 _Seiichi Manyama_, Apr 24 2024