OFFSET
1,3
MATHEMATICA
Union[PowerMod[Range[18], 2, 18]] (* Alonso del Arte, Dec 18 2019 *)
PROG
(Sage) [quadratic_residues(18)] # Zerinvary Lajos, May 24 2009
(Scala) (1 to 18).map(n => (n * n) % 18).toSet.toSeq.sorted // Alonso del Arte, Dec 18 2019
CROSSREFS
KEYWORD
nonn,fini,full
AUTHOR
STATUS
approved