A217469 Multiplicative order of 5 (mod 5*n + 1).

2, 5, 4, 6, 4, 3, 6, 20, 22, 16, 6, 30, 10, 5, 9, 54, 42, 12, 8, 25, 52, 36, 14, 55, 6, 65, 16, 46, 72, 75, 4, 66, 82, 18, 20, 15, 6, 19, 42, 22, 102, 35, 18, 16, 112, 30, 29, 40, 20, 25, 64, 42, 18, 27, 22, 140, 20, 96, 36, 42, 48, 155, 39, 106, 54, 165, 12, 15

Offset: 1

Author

Arkadiusz Wesolowski, Nov 16 2012

Keywords

• nonn

Comments

Least m such that 5*n + 1 divides 5^m - 1.

Links

• Arkadiusz Wesolowski, Table of n, a(n) for n = 1..10000
• Eric Weisstein's World of Mathematics, Multiplicative Order

Crossrefs

Cf. A002326, A003571, A003573.

Programs

GAP

List([1..80],n->OrderMod(5,5*n+1)); # Muniru A Asiru, Feb 26 2019

Mathematica

Table[MultiplicativeOrder[5, 5*n + 1], {n, 68}]

PARI

vector(80, n, znorder(Mod(5, 5*n+1))) \\ Michel Marcus, Feb 09 2015