A076554 a(n)=(-1)^(n+1)/(2n+1)*sum(k=0,n,64^k*B(2k)*C(2n+1,2k)) where B(k) denotes the k-th Bernoulli number.

11, 115, 5591, 502855, 73213571, 15658809595, 4619488631951, 1797261609272335, 891557677006596731, 549227657514325603075, 411352737726238344243911, 368106640606171635113513815

Offset

1,1

Comments

a(2m-1) is of the form 10k+1, a(2m) is of the form 10k+5

Links

Table of n, a(n) for n=1..12.

Prog

(PARI) a(n)=(-1)^(n+1)/(2*n+1)*sum(k=0, n, 64^k*bernfrac(2*k)*binomial(2*n+1, 2*k))

Crossrefs

Sequence in context: A125446 A287838 A271477 * A173616 A287839 A268344

Adjacent sequences: A076551 A076552 A076553 * A076555 A076556 A076557

Keyword

nonn

Author

Benoit Cloitre, Oct 19 2002

Status

approved