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 A330254 #5 Dec 07 2019 08:15:22
%S A330254 1,2,7,24,121,840,5041,40320,423361,3659040,39916801,558835200,
%T A330254 6227020801,87195588480,1536517382401,20922789888000,355687428096001,
%U A330254 7469453633241600,121645100408832001,2453176191578112000,59616236292028416001
%N A330254 Expansion of e.g.f. Sum_{k>=1} sinh(x^k).
%F A330254 E.g.f.: Sum_{k>=1} x^(2*k - 1) / ((2*k - 1)! * (1 - x^(2*k - 1))).
%F A330254 a(n) = n! * Sum_{d|n, d odd} 1 / d!.
%t A330254 nmax = 21; CoefficientList[Series[Sum[Sinh[x^k], {k, 1, nmax}], {x, 0, nmax}], x] Range[0, nmax]! // Rest
%t A330254 Table[n! DivisorSum[n, 1/#! &, OddQ[#] &], {n, 1, 21}]
%Y A330254 Cf. A057625, A132958, A176473, A330255.
%K A330254 nonn
%O A330254 1,2
%A A330254 _Ilya Gutkovskiy_, Dec 07 2019