OFFSET
1,1
EXAMPLE
Since 2 is not a perfect square and there are no solutions to x^2 = 2 mod 26, 2 is in the sequence.
Although 3 is not a perfect square either, there are solutions to x^2 = 3 mod 26, such as x = 9, x = 17, 3 is not in the sequence.
MATHEMATICA
Complement[Range[0, 25], PowerMod[Range[0, 25], 2, 26]] (* Alonso del Arte, Nov 26 2019 *)
PROG
(Scala) val squaresMod26 = (0 to 25).map(n => n * n).map(_ % 26)
(0 to 25).diff(squaresMod26) // Alonso del Arte, Nov 26 2019
CROSSREFS
KEYWORD
nonn,fini,full
AUTHOR
EXTENSIONS
Incorrect term 13 removed by Alonso del Arte, Nov 26 2019
STATUS
approved