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A090643 a(n)=(-1)^(n+1)*(3/4)*(9^n-1)*B(2n) where B(k) denotes the k-th Bernoulli number. 0
0, 1, 2, 13, 164, 3355, 100886, 4185097, 228970568, 15972720439, 1383706615610, 145736540156581, 18339615566386412, 2717605030233712723, 468371974894477377374, 92895125380418204480065, 21008128723110866359626896, 5373571097376355083238621807 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
FORMULA
a(n) = (2n)! [x^(2n)] (3/2) x sin(x)/(2 cos(x)+1). - Ira M. Gessel Feb 23 2012
PROG
(PARI) a(n)=(-1)^(n+1)*(3/4)*(9^n-1)*bernfrac(2*n)
CROSSREFS
Sequence in context: A187927 A252766 A098638 * A132521 A360601 A177448
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Dec 13 2003
STATUS
approved

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Last modified March 28 05:39 EDT 2024. Contains 371235 sequences. (Running on oeis4.)