A099584 Exponent of 3 in factorization of prime(n) - 1.

0, 0, 0, 1, 0, 1, 0, 2, 0, 0, 1, 2, 0, 1, 0, 0, 0, 1, 1, 0, 2, 1, 0, 0, 1, 0, 1, 0, 3, 0, 2, 0, 0, 1, 0, 1, 1, 4, 0, 0, 0, 2, 0, 1, 0, 2, 1, 1, 0, 1, 0, 0, 1, 0, 0, 0, 0, 3, 1, 0, 1, 0, 2, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 3, 0, 0, 2, 0, 1, 0, 1, 0, 3, 1, 0, 0, 1, 0, 1, 0, 0, 5, 0, 1, 0, 0, 0, 2, 3, 1, 0

Offset

1,8

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

seq(padic:-ordp(ithprime(i)-1, 3), i=1..200); # Robert Israel, Mar 02 2018

Mathematica

Table[IntegerExponent[Prime[n] - 1, 3], {n, 110}] (* Bruno Berselli, Aug 05 2013 *)

Prog

(PARI) forprime(p=2, 700, print1(valuation(p-1, 3), ", ")); \\ Bruno Berselli, Aug 05 2013
(Magma) [Valuation(NthPrime(n)-1, 3): n in [1..110]]; // Bruno Berselli, Aug 05 2013

Crossrefs

Equals A007949( A006093(n) ), prime(n)-1 = 3^a(n) * A099585(n).

Cf. A023506.

Sequence in context: A034950 A351127 A331816 * A100563 A325192 A087773

Adjacent sequences: A099581 A099582 A099583 * A099585 A099586 A099587

Keyword

nonn

Author

Ralf Stephan, Oct 24 2004

Status

approved