login
A069989
(-1)^(n+1)/2*sum(k=1,2n,C(2n+1,k)*B(k)*4^k) where C(n,k) are the binomial coefficients, B(k) the Bernoulli numbers.
0
1, 13, 213, 6233, 277865, 17567973, 1495207357, 164827853233, 22846356916689, 3888897476494013, 797512055521085861, 193931677044463586313, 55175478875457172546873, 18157764800352633049290133
OFFSET
1,2
PROG
(PARI) for(n=1, 25, print1(-(-1)^n*sum(i=1, 2*n, binomial(2*n+1, i)*bernfrac(i)*3^i)/2, ", "))
CROSSREFS
Sequence in context: A340431 A251093 A132542 * A140517 A096141 A218475
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, May 01 2002
STATUS
approved