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A124135 a(n)=((-1)^n/6)*sum_{i1+i2+i3+i4=2n} ((2*n)!/(i1! i2! i3! i4!))*B(i1+i2+i3) where B are the Bernoulli numbers. 0
0, 0, 3, 46, 1041, 32592, 1375919, 75858738, 5309829837, 460680712084, 48552875077995, 6111752613274230, 905772678574995593, 156116663818415074776, 30964395850928510817831 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..15.

FORMULA

a(n)=(-1)^(n+1)*{ (9^n/4-4^n+3/4)*B(2n)+1/6}

PROG

(PARI) a(n)=(-1)^(n+1)*((9^n/4-4^n+3/4)*bernfrac(2*n)+1/6)

CROSSREFS

Sequence in context: A278621 A231789 A119401 * A307292 A307290 A193420

Adjacent sequences:  A124132 A124133 A124134 * A124136 A124137 A124138

KEYWORD

nonn

AUTHOR

Benoit Cloitre, Nov 30 2006

STATUS

approved

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Last modified September 25 09:32 EDT 2021. Contains 347654 sequences. (Running on oeis4.)