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 A277475 #10 Nov 08 2017 02:32:04
%S A277475 0,0,2,6,32,300,3576,52234,906688,18229176,416505760,10657541422,
%T A277475 301871501568,9375794555556,316817746172032,11570642333807730,
%U A277475 454152692297009152,19064517871187079408,852278820775206658560,40424330665968520135382,2027524052626732381306880
%N A277475 E.g.f.: -sin(x)*LambertW(-x).
%H A277475 G. C. Greubel, <a href="/A277475/b277475.txt">Table of n, a(n) for n = 0..385</a>
%F A277475 a(n) ~ sin(exp(-1)) * n^(n-1).
%t A277475 CoefficientList[Series[-Sin[x]*LambertW[-x], {x, 0, 20}], x] * Range[0, 20]!
%t A277475 Table[Sum[Binomial[n, k] * Sin[Pi*(n-k)/2] * k^(k-1), {k, 1, n}], {n, 0, 20}] (* _Vaclav Kotesovec_, Oct 28 2016 *)
%o A277475 (PARI) x='x+O('x^50); concat([0,0], Vec(serlaplace(-sin(x)*lambertw(-x)) )) \\ _G. C. Greubel_, Nov 07 2017
%Y A277475 Cf. A000169, A277461, A277473, A277476, A277477.
%K A277475 nonn
%O A277475 0,3
%A A277475 _Vaclav Kotesovec_, Oct 17 2016