A069991 (-1)^(n+1)/14*sum(k=1,2n,C(2n+1,k)*B(k)*7^k) where C(n,k) are the binomial coefficients, B(k) the Bernoulli numbers.

1, 24, 1211, 107426, 14639841, 2833334908, 738420667591, 249285306765270, 105817142655593261, 55162112425933979312, 34643962156837119237651, 25799726424152610741805834, 22479598186937674926509533561

Offset

1,2

Links

Table of n, a(n) for n=1..13.

Prog

(PARI) for(n=1, 25, print1(-(-1)^n*sum(i=1, 2*n, binomial(2*n+1, i)*bernfrac(i)*7^i)/14, ", "))

Crossrefs

Sequence in context: A144618 A042107 A042104 * A035025 A074652 A367706

Adjacent sequences: A069988 A069989 A069990 * A069992 A069993 A069994

Keyword

easy,nonn

Author

Benoit Cloitre, May 01 2002

Status

approved