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 A367487 #14 May 23 2025 13:11:16
%S A367487 1,0,3,18,195,2730,47745,1001742,24523401,686190258,21601161015,
%T A367487 755533274826,29066119327179,1219715093642838,55441103383640793,
%U A367487 2713468284508412430,142269924567096468177,7955396173559375208426,472576083221524737100311
%N A367487 Expansion of e.g.f. 1/(4 - 3*exp(x))^(x/2).
%H A367487 Harvey P. Dale, <a href="/A367487/b367487.txt">Table of n, a(n) for n = 0..372</a>
%F A367487 a(0) = 1; a(n) = (1/2) * Sum_{k=1..n} A367490(k) * binomial(n-1,k-1) * a(n-k).
%t A367487 With[{nn=20},CoefficientList[Series[1/(4-3Exp[x])^(x/2),{x,0,nn}],x] Range[0,nn]!] (* _Harvey P. Dale_, May 23 2025 *)
%o A367487 (PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=sum(j=1, i, j*sum(k=1, j-1, 3^k*(k-1)!*stirling(j-1, k, 2))*binomial(i-1, j-1)*v[i-j+1])/2); v;
%Y A367487 Cf. A354412, A367485.
%Y A367487 Cf. A367490.
%K A367487 nonn
%O A367487 0,3
%A A367487 _Seiichi Manyama_, Nov 19 2023