A216833 Multiplicative order of 2 mod 3*(2n-1).

2, 6, 4, 6, 18, 10, 12, 12, 8, 18, 6, 22, 20, 54, 28, 10, 30, 12, 36, 12, 20, 14, 36, 46, 42, 24, 52, 20, 18, 58, 60, 18, 12, 66, 66, 70, 18, 60, 30, 78, 162, 82, 8, 84, 22, 12, 30, 36, 48, 90, 100, 102, 12, 106, 36, 36, 28, 44, 36, 24, 110, 60, 100, 14, 42

Offset: 1

Author

V. Raman, Sep 17 2012

Keywords

• nonn

Comments

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

Crossrefs

Cf. A003558, A002326, A216469, A216829.

Programs

GAP

List([1..70],n->OrderMod(2,3*(2*n-1))); # Muniru A Asiru, Feb 25 2019

Mathematica

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

PARI

vector(100,n,znorder(Mod(2,3*(2*n-1)))) \\ Joerg Arndt, Sep 14 2012.

Formula

a(n) = 2*A216829(n).