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 A367719 #9 Nov 28 2023 08:39:26
%S A367719 1,1,1,1,25,121,361,3361,42001,275185,1819441,30777121,371238121,
%T A367719 9284332201,131442054745,1454933712961,34120902859681,851562584890081,
%U A367719 12300037440760801,187928965721651905,6019555345508794681,130768735411230580441
%N A367719 E.g.f. satisfies A(x) = exp(x*A(x^3)).
%C A367719 This sequence is different from A354553.
%F A367719 a(0) = 1; a(n) = (n-1)! * Sum_{k=0..floor((n-1)/3)} (3*k+1) * a(k) * a(n-1-3*k) / (k! * (n-1-3*k)!).
%o A367719 (PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=(i-1)!*sum(j=0, (i-1)\3, (3*j+1)*v[j+1]*v[i-3*j]/(j!*(i-1-3*j)!))); v;
%Y A367719 Cf. A138292, A367720.
%Y A367719 Cf. A354553.
%K A367719 nonn
%O A367719 0,5
%A A367719 _Seiichi Manyama_, Nov 28 2023