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 A277483 #9 Nov 10 2017 07:37:19
%S A277483 0,0,2,6,40,340,3984,57050,982528,19616328,446355840,11384327438,
%T A277483 321701896704,9973046260060,336499112011776,12274383608508450,
%U A277483 481282311712489472,20185816487436968208,901732370496365076480,42742176871086712813974,2142556308913381810012160
%N A277483 E.g.f.: -arcsin(x)*LambertW(-x).
%H A277483 G. C. Greubel, <a href="/A277483/b277483.txt">Table of n, a(n) for n = 0..385</a>
%F A277483 a(n) ~ arcsin(exp(-1)) * n^(n-1).
%t A277483 CoefficientList[Series[-ArcSin[x]*LambertW[-x], {x, 0, 20}], x] * Range[0, 20]!
%t A277483 Flatten[{0, Table[Sum[Binomial[n, k] * (1-(-1)^k)/2 * (k-2)!!^2 * (n-k)^(n-k-1), {k, 1, n-1}], {n, 1, 20}]}] (* _Vaclav Kotesovec_, Oct 28 2016 *)
%o A277483 (PARI) x='x+O('x^50); concat([0,0], Vec(serlaplace(- asin(x)*lambertw(-x) ))) \\ _G. C. Greubel_, Nov 08 2017
%Y A277483 Cf. A000169, A277469, A277473, A277484.
%K A277483 nonn
%O A277483 0,3
%A A277483 _Vaclav Kotesovec_, Oct 17 2016