OFFSET
1,1
MATHEMATICA
Complement[Range[0, 27], PowerMod[Range[28], 2, 28]] (* Alonso del Arte, Nov 28 2019 *)
PROG
(Scala) val squaresMod28 = (1 to 28).map(n => n * n).map(_ % 28)
(0 to 27).diff(squaresMod28) // Alonso del Arte, Nov 28 2019
CROSSREFS
KEYWORD
nonn,fini,full
AUTHOR
STATUS
approved