A054715 Number of powers of 15 modulo n.

1, 1, 2, 2, 2, 2, 1, 2, 3, 2, 5, 3, 12, 1, 2, 2, 8, 3, 18, 3, 2, 5, 22, 3, 3, 12, 4, 2, 28, 2, 10, 2, 6, 8, 2, 4, 36, 18, 13, 3, 40, 2, 21, 10, 3, 22, 46, 3, 7, 3, 9, 12, 13, 4, 6, 2, 19, 28, 29, 3, 15, 10, 3, 4, 13, 6, 11, 8, 23, 2, 35, 4, 72, 36, 3, 18, 5, 13, 26, 3, 5, 40, 82, 3, 9, 21, 29

Offset

1,3

Links

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

Mathematica

a[n_] := Module[{e = IntegerExponent[n, {3, 5}]}, Max[e] + MultiplicativeOrder[15, n/Times @@ ({3, 5}^e)]]; Array[a, 100] (* Amiram Eldar, Aug 25 2024 *)

Crossrefs

Cf. A054703 (base 2), A054704 (3), A054705 (4), A054706 (5), A054707 (6), A054708 (7), A054709 (8), A054717 (9), A054710 (10), A351524 (11), A054712 (12), A054713 (13), A054714 (14), A054716 (16).

Sequence in context: A240301 A289641 A209312 * A254668 A306250 A145443

Adjacent sequences: A054712 A054713 A054714 * A054716 A054717 A054718

Keyword

easy,nonn

Author

Henry Bottomley, Apr 20 2000

Status

approved