OFFSET
1,3
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..425
FORMULA
a(n) ~ sqrt(Pi/3) * n^(n+1/2) / 2^(n+1/2). - Vaclav Kotesovec, Dec 20 2014
MATHEMATICA
Table[Sum[i^(n-i)*(n-i)^i, {i, 0, n}], {n, 20}] (* Harvey P. Dale, Jan 14 2017 *)
PROG
(PARI) for(n=1, 25, print1(sum(k=0, n, k^(n-k)*(n-k)^k), ", ")) \\ G. C. Greubel, Jan 25 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Olivier Gérard, Jun 23 2001
EXTENSIONS
Prior Mathematica program deleted by Harvey P. Dale, Jan 14 2017
STATUS
approved