A054709 Number of powers of 8 modulo n.

1, 2, 2, 2, 4, 3, 1, 2, 2, 5, 10, 3, 4, 2, 4, 3, 8, 3, 6, 5, 2, 11, 11, 3, 20, 5, 6, 2, 28, 5, 5, 3, 10, 9, 4, 3, 12, 7, 4, 5, 20, 3, 14, 11, 4, 12, 23, 4, 7, 21, 8, 5, 52, 7, 20, 2, 6, 29, 58, 5, 20, 6, 2, 3, 4, 11, 22, 9, 22, 5, 35, 3, 3, 13, 20, 7, 10, 5, 13, 6, 18, 21, 82, 3, 8, 15, 28

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1000 from David W. Wilson)

Formula

a(n) = valuation(4*n, 8) + A007739(n). - Amiram Eldar, Aug 25 2024

Mathematica

a[n_] := IntegerExponent[4*n, 8] + MultiplicativeOrder[8, n/2^IntegerExponent[n, 2]]; Array[a, 100] (* Amiram Eldar, Aug 25 2024 *)

Crossrefs

Cf. A007739.

Cf. A054703 (base 2), A054704 (3), A054705 (4), A054706 (5), A054707 (6), A054708 (7), A054717 (9), A054710 (10), A351524 (11), A054712 (12), A054713 (13), A054714 (14), A054715 (15), A054716 (16).

Sequence in context: A064025 A182154 A273875 * A121806 A056944 A283681

Adjacent sequences: A054706 A054707 A054708 * A054710 A054711 A054712

Keyword

easy,nonn

Author

Henry Bottomley, Apr 20 2000

Status

approved