# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a277477 Showing 1-1 of 1 %I A277477 #9 Nov 08 2017 02:32:21 %S A277477 0,1,2,6,52,540,6846,104832,1883848,38889360,907247770,23608391840, %T A277477 678039307452,21305543325248,727095737061526,26781816978470400, %U A277477 1059020025979194128,44746083421419997440,2011929587198990154162,95918808101232854969856 %N A277477 E.g.f.: -cos(x)*LambertW(-x). %H A277477 G. C. Greubel, Table of n, a(n) for n = 0..385 %F A277477 a(n) ~ cos(exp(-1)) * n^(n-1). %t A277477 CoefficientList[Series[-Cos[x]*LambertW[-x], {x, 0, 20}], x] * Range[0, 20]! %t A277477 Table[Sum[Binomial[n, k] * Cos[Pi*(n-k)/2] * k^(k-1), {k, 1, n}], {n, 0, 20}] (* _Vaclav Kotesovec_, Oct 28 2016 *) %o A277477 (PARI) x='x+O('x^50); concat([0], Vec(serlaplace(-cos(x)*lambertw(-x)))) \\ _G. C. Greubel_, Nov 07 2017 %Y A277477 Cf. A000169, A277462, A277473, A277475, A277478. %K A277477 nonn %O A277477 0,3 %A A277477 _Vaclav Kotesovec_, Oct 17 2016 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE