OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
pr=-6; Select[Range[2, 2000], MultiplicativeOrder[pr, # ] == EulerPhi[ # ] &]
PROG
(PARI) is(n)=gcd(n, 6)==1 && znorder(Mod(-6, n))==eulerphi(n) && n>1 \\ Charles R Greathouse IV, Feb 23 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
T. D. Noe, Nov 12 2009
STATUS
approved