A028769 Nonsquares mod 56.

2, 3, 5, 6, 7, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 24, 26, 27, 29, 30, 31, 33, 34, 35, 37, 38, 39, 40, 41, 42, 43, 45, 46, 47, 48, 50, 51, 52, 53, 54, 55

Offset

1,1

Links

Table of n, a(n) for n=1..44.

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

Cf. A010417.

Sequence in context: A259444 A071591 A089105 * A094784 A085971 A175082

Adjacent sequences: A028766 A028767 A028768 * A028770 A028771 A028772

Keyword

nonn,fini,full,easy

Author

N. J. A. Sloane

Status

approved