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 A375175 #15 Feb 16 2025 08:34:07
%S A375175 1,1,7,63,713,9753,156111,2858103,58845105,1344371793,33713484151,
%T A375175 919838859151,27105053988793,857310780134825,28953291147179007,
%U A375175 1039373409620929671,39505610599553955809,1584411299793530257697,66846625774893448843879
%N A375175 Expansion of e.g.f. exp( (exp( (exp(4*x) - 1)/2 ) - 1)/2 ).
%H A375175 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/BellPolynomial.html">Bell Polynomial</a>.
%F A375175 a(n) = Sum_{k=0..n} 4^(n-k) * Stirling2(n,k) * A004211(k) = 4^n * Sum_{k=0..n} (1/2)^k * Stirling2(n,k) * Bell_k(1/2), where Bell_n(x) is n-th Bell polynomial.
%o A375175 (PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(exp((exp((exp(4*x)-1)/2)-1)/2)))
%Y A375175 Cf. A080893, A375173.
%Y A375175 Cf. A004211.
%K A375175 nonn
%O A375175 0,3
%A A375175 _Seiichi Manyama_, Aug 02 2024