A216829 2*a(n) is the multiplicative order of 2 mod 3*(2n-1).

1, 3, 2, 3, 9, 5, 6, 6, 4, 9, 3, 11, 10, 27, 14, 5, 15, 6, 18, 6, 10, 7, 18, 23, 21, 12, 26, 10, 9, 29, 30, 9, 6, 33, 33, 35, 9, 30, 15, 39, 81, 41, 4, 42, 11, 6, 15, 18, 24, 45, 50, 51, 6, 53, 18, 18, 14, 22, 18, 12, 55, 30, 50, 7, 21, 65, 9, 54, 34, 69, 69

Offset

1,2

Comments

2*a(n) is the smallest m such that 3*(2n-1) | (2^m+1).

Links

Muniru A Asiru, Table of n, a(n) for n = 1..10000

Formula

a(n) = A216833(n)/2.

Mathematica

Table[MultiplicativeOrder[2, 3*(2*n-1)], {n, 100}]/2 (* T. D. Noe, Sep 19 2012 *)

Prog

(PARI) vector(100, n, znorder(Mod(2, 3*(2*n-1)))/2) \\ Joerg Arndt, Sep 14 2012.
(GAP) List([1..70], n->OrderMod(2, 3*(2*n-1))/2); # Muniru A Asiru, Feb 26 2019

Crossrefs

Cf. A003558, A002326, A216469, A216833.

Sequence in context: A376859 A261999 A360701 * A331846 A332310 A022460

Adjacent sequences: A216826 A216827 A216828 * A216830 A216831 A216832

Keyword

nonn

Author

V. Raman, Sep 17 2012

Status

approved