A069990 (-1)^(n+1)/5*sum(k=1,2n,C(2n+1,k)*B(k)*5^k) where C(n,k) are the binomial coefficients, B(k) the Bernoulli numbers.

1, 15, 389, 17687, 1230957, 121576879, 16166877205, 2784640846791, 603078760252733, 160399574539581023, 51396542533525536741, 19528343388372578867575, 8681260357657270101974029

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)*5^i)/5, ", "))

Crossrefs

Sequence in context: A374000 A129615 A286139 * A157581 A143001 A373872

Adjacent sequences: A069987 A069988 A069989 * A069991 A069992 A069993

Keyword

easy,nonn

Author

Benoit Cloitre, May 01 2002

Status

approved