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 A330544 #4 Dec 18 2019 09:02:37
%S A330544 1,1,2,14,48,424,3360,30288,276864,3591936,46241280,599212800,
%T A330544 9205954560,142744412160,2554915184640,47649718609920,907617573273600,
%U A330544 18296536869273600,413470794456760320,9130651338347642880,221996730181563187200
%N A330544 Expansion of e.g.f. Product_{k>=1} (1 + arctanh(x^k)).
%F A330544 E.g.f.: exp(Sum_{k>=1} Sum_{d|k} (-1)^(d + 1) * arctanh(x^(k/d))^d / d).
%t A330544 nmax = 20; CoefficientList[Series[Product[(1 + ArcTanh[x^k]), {k, 1, nmax}], {x, 0, nmax}], x] Range[0, nmax]!
%t A330544 nmax = 20; CoefficientList[Series[Exp[Sum[Sum[(-1)^(d + 1) ArcTanh[x^(k/d)]^d/d, {d, Divisors[k]}], {k, 1, nmax}]], {x, 0, nmax}], x] Range[0, nmax]!
%Y A330544 Cf. A010050, A270664, A330543.
%K A330544 nonn
%O A330544 0,3
%A A330544 _Ilya Gutkovskiy_, Dec 17 2019