OFFSET
1,1
EXAMPLE
x^2 = 20 mod 60 has no solutions, so 20 is in the sequence.
x^2 = 21 mod 60 has the following solutions: x = 9, x = 21, x = 39, x = 51. Hence 21 is not in the sequence.
MATHEMATICA
Complement[Range[59], PowerMod[Range[60], 2, 60]] (* Alonso del Arte, Jan 13 2017 *)
PROG
(Scala) (0 to 59).diff((1 to 60).map(n => n * n % 60)) // Alonso del Arte, Jan 03 2020
CROSSREFS
KEYWORD
nonn,fini,full,easy
AUTHOR
STATUS
approved