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 A308337 #6 May 21 2019 02:47:26
%S A308337 1,1,4,21,146,1210,11894,133000,1677668,23439684,359651232,6000427884,
%T A308337 108157599120,2092493844480,43240336406136,950021322002904,
%U A308337 22108068716440272,543048769028068944,14037848562783308160,380851191359082217488,10818262594065294568416
%N A308337 Expansion of e.g.f. exp(-1 + Product_{k>=1} 1/(1 - x^k/k)).
%F A308337 a(0) = 1; a(n) = Sum_{k=1..n} binomial(n-1,k-1)*A007841(k)*a(n-k).
%t A308337 nmax = 20; CoefficientList[Series[Exp[Product[1/(1 - x^k/k), {k, 1, nmax}] - 1], {x, 0, nmax}], x] Range[0, nmax]!
%Y A308337 Cf. A007841, A143463, A308338.
%K A308337 nonn
%O A308337 0,3
%A A308337 _Ilya Gutkovskiy_, May 20 2019