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 A377553 #10 Nov 01 2024 09:32:50
%S A377553 1,2,14,174,3176,77010,2336892,85316714,3644408336,178412603778,
%T A377553 9851421767060,605826315779322,41068369222584024,3042849619010389058,
%U A377553 244657525386435161756,21217387476442659806250,1974219906922046702054432,196191093901292764305110274,20739322455031604846405387556
%N A377553 Expansion of e.g.f. (1/x) * Series_Reversion( x/(1 + x*exp(x))^2 ).
%H A377553 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A377553 E.g.f. satisfies A(x) = (1 + x * A(x) * exp(x*A(x)))^2.
%F A377553 E.g.f.: B(x)^2, where B(x) is the e.g.f. of A364982.
%F A377553 a(n) = (n!/(n+1)) * Sum_{k=0..n} k^(n-k) * binomial(2*n+2,k)/(n-k)!.
%o A377553 (PARI) a(n) = n!*sum(k=0, n, k^(n-k)*binomial(2*n+2, k)/(n-k)!)/(n+1);
%Y A377553 Cf. A161633, A377554.
%Y A377553 Cf. A364982.
%K A377553 nonn
%O A377553 0,2
%A A377553 _Seiichi Manyama_, Nov 01 2024