A053450 - OEIS

A053450

Multiplicative order of 7 mod n, where gcd(n,7) = 1.

1, 1, 1, 2, 4, 1, 2, 3, 4, 10, 2, 12, 4, 2, 16, 3, 3, 4, 10, 22, 2, 4, 12, 9, 7, 4, 15, 4, 10, 16, 6, 9, 3, 12, 4, 40, 6, 10, 12, 22, 23, 2, 4, 16, 12, 26, 9, 20, 3, 7, 29, 4, 60, 15, 8, 12, 10, 66, 16, 22, 70, 6, 24, 9, 4, 6, 12, 78, 4, 27, 40, 41, 16, 6, 7, 10, 88, 12, 22, 15, 23, 12, 4

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OFFSET

1,4

COMMENTS

Essentially the same as A050979. [R. J. Mathar, Oct 13 2008]

LINKS

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

MATHEMATICA

MultiplicativeOrder[7, #] & /@ Select[ Range@ 100, GCD[7, #] == 1 &] (* Robert G. Wilson v, Apr 05 2011 *)

PROG

(PARI) lista(nn) = {for (n=1, nn, if (gcd(n, 7) == 1, print1(znorder(Mod(7, n)), ", ")); ); } \\ Michel Marcus, Feb 06 2015

(GAP) List(Filtered([1..120], n->Gcd(n, 7)=1), n->OrderMod(7, n)); # Muniru A Asiru, Feb 25 2019