A090823 a(n) = (3/2)*(1/p)*(2*p+1)*(3^p+1)*B(2*p) where p = prime(n) and where B(k) denotes the k-th Bernoulli number.

61, 8205, 3440347021, 7080447489597, 171336855102372210685, 1747517658865390518778893, 610345691966794096778276272763149, 49983985045539556672075839852554462798428935229, 3860144322784333181994546680342901473505673190876301

Offset

3,1

Links

Amiram Eldar, Table of n, a(n) for n = 3..61

Formula

a(n) == 1 (mod prime(n)).

Mathematica

Table[p=Prime[n]; 3/(2p) (2p+1)(3^p+1)BernoulliB[2p], {n, 3, 10}] (* Harvey P. Dale, Aug 21 2013 *)

Prog

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

Crossrefs

Cf. A027641, A027642.

Sequence in context: A219113 A210686 A103915 * A093261 A062638 A261238

Adjacent sequences: A090820 A090821 A090822 * A090824 A090825 A090826

Keyword

nonn

Author

Benoit Cloitre, Feb 11 2004

Status

approved