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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..14.

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: A196328 A251093 A132542 * A140517 A096141 A218475

Adjacent sequences:  A069986 A069987 A069988 * A069990 A069991 A069992

KEYWORD

easy,nonn

AUTHOR

Benoit Cloitre, May 01 2002

STATUS

approved

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Last modified November 21 05:01 EST 2017. Contains 294988 sequences.