OFFSET
1,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..445
FORMULA
a(n)= (n-1)*(n+1)*n! - sum( i!, i=1..n-1)
MATHEMATICA
Table[Plus @@ Prepend[Table[(n + 1)! - i!, {i, n, 2, -1}], (n)! - 1], {n, 0, 20}]
PROG
(PARI) for(n=1, 25, print1((n^2-1)*n! - sum(k=1, n-1, k!), ", ")) \\ G. C. Greubel, Jun 09 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Olivier Gérard, Nov 02 2012
STATUS
approved