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 A297209 #9 Mar 27 2019 03:50:51
%S A297209 0,1,-3,9,-32,148,-853,6027,-49576,470624,-5005137,59454923,
%T A297209 -774282632,11035740844,-169997137269,2826070412955,-50256453936368,
%U A297209 954657085889760,-19247168446169665,411277539407862707,-9269937746437524256,220085825544691181500,-5483977295221312280757
%N A297209 Expansion of e.g.f. log(1 + arcsin(x))*exp(-x).
%e A297209 log(1 + arcsin(x))*exp(-x) = x/1! - 3*x^2/2! + 9*x^3/3! - 32*x^4/4! + 148*x^5/5! - 853*x^6/6! + ...
%p A297209 a:=series(log(1+arcsin(x))*exp(-x),x=0,23): seq(n!*coeff(a,x,n),n=0..22); # _Paolo P. Lava_, Mar 26 2019
%t A297209 nmax = 22; CoefficientList[Series[Log[1 + ArcSin[x]] Exp[-x], {x, 0, nmax}], x] Range[0, nmax]!
%t A297209 nmax = 22; CoefficientList[Series[Log[1 - I Log[I x + Sqrt[1 - x^2]]] Exp[-x], {x, 0, nmax}], x] Range[0, nmax]!
%o A297209 (PARI) x='x+O('x^99); concat([0], Vec(serlaplace(exp(-x)*log(1+asin(x))))) \\ _Altug Alkan_, Dec 28 2017
%Y A297209 Cf. A009337, A009356, A009374, A009393, A189815, A296436, A297210, A297211, A297213.
%K A297209 sign
%O A297209 0,3
%A A297209 _Ilya Gutkovskiy_, Dec 27 2017