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 A330540 #5 Dec 17 2019 19:14:19
%S A330540 1,1,2,11,48,349,2640,23673,231504,2693241,33313680,446104845,
%T A330540 6572693160,103319528805,1750718151000,31865325610545,607019625223200,
%U A330540 12253084499034225,263721891513921120,5900460781451357205,139338570648068278200
%N A330540 Expansion of e.g.f. Product_{k>=1} (1 + arcsinh(x^k)).
%F A330540 E.g.f.: exp(Sum_{k>=1} Sum_{d|k} (-1)^(d + 1) * arcsinh(x^(k/d))^d / d).
%t A330540 nmax = 20; CoefficientList[Series[Product[(1 + ArcSinh[x^k]), {k, 1, nmax}], {x, 0, nmax}], x] Range[0, nmax]!
%t A330540 nmax = 20; CoefficientList[Series[Exp[Sum[Sum[(-1)^(d + 1) ArcSinh[x^(k/d)]^d/d, {d, Divisors[k]}], {k, 1, nmax}]], {x, 0, nmax}], x] Range[0, nmax]!
%Y A330540 Cf. A001818, A270294, A330539.
%K A330540 nonn
%O A330540 0,3
%A A330540 _Ilya Gutkovskiy_, Dec 17 2019