A227991 Highest power of 3 dividing prime(n)+1.

3, 1, 3, 1, 3, 1, 9, 1, 3, 3, 1, 1, 3, 1, 3, 27, 3, 1, 1, 9, 1, 1, 3, 9, 1, 3, 1, 27, 1, 3, 1, 3, 3, 1, 3, 1, 1, 1, 3, 3, 9, 1, 3, 1, 9, 1, 1, 1, 3, 1, 9, 3, 1, 9, 3, 3, 27, 1, 1, 3, 1, 3, 1, 3, 1, 3, 1, 1, 3, 1, 3, 9, 1, 1, 1, 3, 3, 1, 3, 1, 3, 1, 27, 1, 1, 3, 9

Offset

1,1

Links

Bruno Berselli, Table of n, a(n) for n = 1..1000

Formula

a(n) = 3^A227990(n).

Mathematica

Table[3^IntegerExponent[Prime[n] + 1, 3], {n, 100}]

Prog

(PARI) forprime(p=2, 700, print1(3^valuation(p+1, 3), ", "));
(Magma) [3^Valuation(NthPrime(n)+1, 3): n in [1..100]];

Crossrefs

Cf. A068503 (highest power of 3 dividing prime(n)-1), A068504 (highest power of 2 dividing prime(n)+1), A227990.

Sequence in context: A348611 A070039 A373032 * A319137 A074122 A372834

Adjacent sequences: A227988 A227989 A227990 * A227992 A227993 A227994

Keyword

nonn

Author

Bruno Berselli, Aug 05 2013

Status

approved