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 A352887 #9 Apr 07 2022 10:43:14
%S A352887 1,1,3,14,84,634,5740,60626,731852,9938670,149966116,2489148386,
%T A352887 45070961740,884107377360,18676602726734,422721143355808,
%U A352887 10205605681874952,261789688633794528,7110331886095458918,203848868169846041430,6151813078359073154568
%N A352887 Expansion of e.g.f. 1/(1 - Sum_{k>=1} phi(k)*x^k/k!), where phi is the Euler totient function A000010.
%F A352887 a(0) = 1; a(n) = Sum_{k=1..n} phi(k) * binomial(n,k) * a(n-k).
%o A352887 (PARI) my(N=40, x='x+O('x^N)); Vec(serlaplace(1/(1-sum(k=1, N, eulerphi(k)*x^k/k!))))
%o A352887 (PARI) a(n) = if(n==0, 1, sum(k=1, n, eulerphi(k)*binomial(n, k)*a(n-k)));
%Y A352887 Cf. A000010, A159929, A300011, A318811.
%K A352887 nonn
%O A352887 0,3
%A A352887 _Seiichi Manyama_, Apr 07 2022