OFFSET
1,4
FORMULA
a(i)=0 for i=1, 2, 3; a(n) = n^3*(n+1)^(n-4), n >= 4.
E.g.f.: (9*W(-x)^2-14*W(-x)^3+3*W(-x)^4-9*x^2-32*x^3-81*x^4)/(72*x), W(x) principal branch of Lambert's function.
MAPLE
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wolfdieter Lang, Jun 20 2000
STATUS
approved