A068503 Highest power of 3 dividing prime(n)-1.

1, 1, 1, 3, 1, 3, 1, 9, 1, 1, 3, 9, 1, 3, 1, 1, 1, 3, 3, 1, 9, 3, 1, 1, 3, 1, 3, 1, 27, 1, 9, 1, 1, 3, 1, 3, 3, 81, 1, 1, 1, 9, 1, 3, 1, 9, 3, 3, 1, 3, 1, 1, 3, 1, 1, 1, 1, 27, 3, 1, 3, 1, 9, 1, 3, 1, 3, 3, 1, 3, 1, 1, 3, 3, 27, 1, 1, 9, 1, 3, 1, 3, 1, 27, 3, 1, 1, 3, 1, 3, 1, 1, 243, 1, 3, 1, 1, 1, 9, 27

Offset

1,4

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

a(n) = A038500(A006093(n)). - Michel Marcus, Nov 24 2013

a(n) = 3^A099584(n). - Michel Marcus, Nov 24 2013

Mathematica

a[n_] := 3^IntegerExponent[Prime[n] - 1, 3]; Array[a, 100] (* Amiram Eldar, May 14 2022 *)

Prog

(PARI) a(n) = 3^valuation(prime(n)-1, 3); \\ Michel Marcus, Nov 24 2013

Crossrefs

Cf. A006093, A038500, A099584.

Sequence in context: A300251 A016572 A072860 * A073575 A363533 A146431

Adjacent sequences: A068500 A068501 A068502 * A068504 A068505 A068506

Keyword

easy,nonn

Author

Benoit Cloitre, Mar 11 2002

Status

approved