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 A143925 #17 Jul 24 2025 09:32:00
%S A143925 1,1,3,25,397,10061,369061,18415825,1197307161,98248658905,
%T A143925 9928361978281,1211474323983221,175635827999270629,
%U A143925 29845580180227776277,5876070628821158239293,1327055145216772464211321,340793190982323564066166321,98752652958563191504390390577
%N A143925 E.g.f. A(x) satisfies A(x) = exp(x + x^2*A'(x)).
%H A143925 Vaclav Kotesovec, <a href="/A143925/b143925.txt">Table of n, a(n) for n = 0..250</a>
%F A143925 a(n) ~ c * (n!)^2, where c = 0.80799863989712622039... - _Vaclav Kotesovec_, Feb 22 2014
%F A143925 a(0) = 1; a(n) = a(n-1) + Sum_{k=0..n-1} (1 + k) * k * binomial(n-1,k) * a(k) * a(n-1-k). - _Seiichi Manyama_, Jul 24 2025
%o A143925 (PARI) {a(n)=local(A=1+x);for(i=0,n,A=exp(x+x^2*deriv(A)+x*O(x^n)));n!*polcoeff(A,n)}
%Y A143925 Cf. A386505, A386506, A386507, A386508, A386509.
%Y A143925 Cf. A386510, A386511, A386512, A386513.
%Y A143925 Cf. A156326.
%K A143925 nonn
%O A143925 0,3
%A A143925 _Paul D. Hanna_, Sep 06 2008