OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
pr=20; Select[Prime[Range[200]], MultiplicativeOrder[pr, # ] == #-1 &]
Join[{3, 13, 17}, Select[Prime[Range[200]], PrimitiveRoot[#, 20]==20&]] (* Harvey P. Dale, Mar 22 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved