OFFSET
1,1
MATHEMATICA
Complement[Range[0, 55], PowerMod[Range[56], 2, 56]] (* Alonso del Arte, Dec 28 2019 *)
PROG
(PARI) is(n)=!issquare(Mod(n, 56)) && n>0 && n<56 \\ Charles R Greathouse IV, Apr 27 2015
(Scala) (0 to 55).diff((1 to 56).map(n => (n * n) % 56)) // Alonso del Arte, Dec 28 2019
CROSSREFS
KEYWORD
nonn,fini,full,easy
AUTHOR
STATUS
approved