OFFSET
0,1
PROG
(PARI) a(n)=if(n<1, 2, floor(n!*2^n*exp(1))-2*n*floor((n-1)!*2^(n-1)*exp(1)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Jun 03 2003
STATUS
approved