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 A364982 #13 Aug 15 2023 11:57:39
%S A364982 1,1,6,69,1204,28345,842406,30282385,1278159240,61979238513,
%T A364982 3395850105610,207490382754721,13989267347891628,1031687145559176457,
%U A364982 82618837044274734126,7139807492658000170865,662286433378726179463696,65635135687587192429274849
%N A364982 E.g.f. satisfies A(x) = 1 + x*A(x)^2*exp(x*A(x)^2).
%F A364982 a(n) = (n!/(2*n+1)) * Sum_{k=0..n} k^(n-k) * binomial(2*n+1,k)/(n-k)!.
%o A364982 (PARI) a(n) = n!*sum(k=0, n, k^(n-k)*binomial(2*n+1, k)/(n-k)!)/(2*n+1);
%Y A364982 Cf. A213644, A295238.
%Y A364982 Cf. A161633, A364986, A364989.
%Y A364982 Cf. A001764.
%K A364982 nonn
%O A364982 0,3
%A A364982 _Seiichi Manyama_, Aug 15 2023