A239202 Multiplicative order of phi(n) modulo n when gcd(phi(n),n)=1.

1, 1, 2, 2, 2, 2, 2, 4, 2, 2, 2, 2, 2, 10, 6, 2, 2, 2, 2, 8, 2, 2, 2, 12, 2, 22, 2, 2, 15, 2, 2, 4, 28, 2, 12, 36, 2, 2, 2, 2, 2, 2, 44, 48, 20, 2, 2, 18, 2, 2, 46, 6, 28, 2, 2, 2, 52, 22, 2, 2, 2, 58, 2, 2, 18, 80, 2, 2, 2, 2, 45, 2, 70, 28, 6, 48, 2, 2, 2

Offset: 1

Author

Alexander Gruber, Mar 12 2014

Keywords

• nonn

Examples

			For n = 8: the 8th entry of A003277 is 15, and phi(15) = 8 has multiplicative order 4 modulo 15, so a(8) = 4.
		

Links

• Giovanni Resta, Table of n, a(n) for n = 1..10000

Crossrefs

Indexed by A003277.

Programs

Mathematica

MultiplicativeOrder[EulerPhi[#], #] & /@ Select[Range[1000], GCD[#, EulerPhi[#]] == 1 &]

PARI

lista(nn) = {for(n=1, nn, my(ephi = eulerphi(n)); if (gcd(ephi, n) == 1, print1(znorder(Mod(ephi, n)), ", ")););} \\ Michel Marcus, Feb 09 2015