OFFSET
2,1
LINKS
FORMULA
a(n)=n^n-2*(n-1)^n+(n-2)^n (n=2,3,...)
MAPLE
a:=n->n^n-2*(n-1)^n+(n-2)^n;
MATHEMATICA
Drop[Table[Sum[(-1)^k Binomial[2, k] (n-k)^n, {k, 0, 2}], {n, 1, 20}], 1] (* Geoffrey Critzer, Dec 23 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Aleksandar M. Janjic and Milan Janjic, Feb 18 2007
EXTENSIONS
Entries checked by N. J. A. Sloane, Mar 08 2007
STATUS
approved