A090647 a(n)=(-1)^(n+1)*(7/8)*(49^n-1)*B(2n) where B(k) denotes the k-th Bernoulli number.

0, 7, 70, 2451, 168140, 18724685, 3065490210, 692352720199, 206231512032280, 78326336951247393, 36942519649032690350, 21183831880266815272667, 14513757566643671668200420, 11709262576429836293006370421

Offset

0,2

Links

Table of n, a(n) for n=0..13.

Mathematica

Table[(-1)^(n+1)*7/8*(49^n-1)*BernoulliB[2n], {n, 0, 20}] (* Harvey P. Dale, May 24 2016 *)

Prog

(PARI) a(n)=(-1)^(n+1)*(7/8)*(49^n-1)*bernfrac(2*n)

Crossrefs

Sequence in context: A362775 A365031 A097630 * A200929 A111462 A045713

Adjacent sequences: A090644 A090645 A090646 * A090648 A090649 A090650

Keyword

nonn

Author

Benoit Cloitre, Dec 13 2003

Status

approved