OFFSET
1,1
MATHEMATICA
Complement[Range[0, 80], PowerMod[Range[81], 2, 81]] (* Alonso del Arte, Dec 27 2019 *)
PROG
(Scala) (0 to 80).diff((1 to 81).map(n => (n * n) % 81)) // Alonso del Arte, Dec 27 2019
CROSSREFS
KEYWORD
nonn,fini,full,easy
AUTHOR
STATUS
approved