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A054715
Number of powers of 15 modulo n.
15
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
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
KEYWORD
easy,nonn
AUTHOR
Henry Bottomley, Apr 20 2000
STATUS
approved