OFFSET
1,3
FORMULA
a(n)=(-1)^(n+1)*{ (9^n/4-4^n+3/4)*B(2n)+1/6}
PROG
(PARI) a(n)=(-1)^(n+1)*((9^n/4-4^n+3/4)*bernfrac(2*n)+1/6)
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Nov 30 2006
STATUS
approved