A028791 Nonsquares mod 78.

2, 5, 6, 7, 8, 11, 14, 15, 17, 18, 19, 20, 21, 23, 24, 26, 28, 29, 31, 32, 33, 34, 35, 37, 38, 41, 44, 45, 46, 47, 50, 53, 54, 56, 57, 58, 59, 60, 62, 63, 65, 67, 68, 70, 71, 72, 73, 74, 76, 77

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• fini
• full
• easy

Crossrefs

Cf. A010439.

Programs

Mathematica

Complement[Range[0, 77], PowerMod[Range[78], 2, 78]] (* Alonso del Arte, Dec 26 2019 *)

PARI

for(k=0, 78, if(!issquare(Mod(k, 78)), print1(k, ", "))) \\ Hugo Pfoertner, Dec 02 2019

Scala

(0 to 77).diff((1 to 78).map(n => (n * n) % 78)) // Alonso del Arte, Dec 26 2019

Extensions

Incorrect term 39 removed by Alonso del Arte, Dec 01 2019