OFFSET
4,2
COMMENTS
a(n) = A243098(n,4)/6. - Alois P. Heinz, Aug 19 2014
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 4..200
FORMULA
a(n) = (n-1)!/(k-1)!*Sum_{i=0..floor((n-k)/k)} 1/(i!*k^i)*n^(n-(i+1)*k)/(n-(i+1)*k)!, k=4.
a(n) ~ 1/6*exp(1/4)*n^(n-1). - Vaclav Kotesovec, Nov 27 2012
MATHEMATICA
CoefficientList[Series[E^(1/4*LambertW[-x]^4)/6, {x, 0, 20}], x]* Range[0, 20]! (* Vaclav Kotesovec, Nov 27 2012 *)
PROG
(PARI) x='x+O('x^30); Vec(serlaplace(exp(lambertw(-x)^4/4)/3! - 1/3!)) \\ G. C. Greubel, Feb 19 2018
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Vladeta Jovovic, Apr 10 2001
STATUS
approved