A090813 a(n)=3*(3^prime(n)-1)*B(2*prime(n)) where prime(n)=n-th prime and B(k) denotes the k-th Bernoulli number.

55, 7651, 3290729563, 6818200140583, 166441513807473717727, 1702709510836284027532747, 597359613401618666812910561358019, 49136798858325589887577115786547403314116681479

Offset

3,1

Comments

Appears to be an integer value for n=3 up to 250.

Links

Table of n, a(n) for n=3..10.

Prog

(PARI) a(n)=3*(3^prime(n)-1)*bernfrac(2*prime(n))

Crossrefs

Sequence in context: A028471 A004708 A269500 * A145617 A105842 A113632

Adjacent sequences: A090810 A090811 A090812 * A090814 A090815 A090816

Keyword

nonn

Author

Benoit Cloitre, Feb 11 2004

Status

approved