OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
pr=28; Select[Prime[Range[200]], MultiplicativeOrder[pr, # ] == #-1 &]
Join[{5, 11, 13, 17, 23}, Select[Prime[Range[150]], MemberQ[ PrimitiveRootList[ #], 28]&]] (* Harvey P. Dale, Jan 17 2022 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved