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 A069988 (-1)^(n+1)/6*sum(k=1,2n+1,C(2n+1,k)*B(k)*3^k) where C(n,k) are the binomial coefficients, B(k) the Bernoulli numbers. 0
 0, 1, 8, 135, 3386, 120469, 5767884, 357666403, 27886211102, 2670067220337, 308003491726640, 42129829536116671, 6742323657098884098, 1248097176923675241805, 264614795104954119229076 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS PROG (PARI) for(n=1, 25, print1(-(-1)^n*sum(i=1, 2*n+1, binomial(2*n+1, i)*bernfrac(i)*3^i)/6, ", ")) CROSSREFS Sequence in context: A003375 A007032 A215553 * A229237 A291699 A292914 Adjacent sequences: A069985 A069986 A069987 * A069989 A069990 A069991 KEYWORD easy,nonn AUTHOR Benoit Cloitre, May 01 2002 STATUS approved

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Last modified December 6 21:00 EST 2022. Contains 358648 sequences. (Running on oeis4.)