A136804 Nonsquares mod 257.

3, 5, 6, 7, 10, 12, 14, 19, 20, 24, 27, 28, 33, 37, 38, 39, 40, 41, 43, 45, 47, 48, 51, 53, 54, 55, 56, 63, 65, 66, 69, 71, 74, 75, 76, 77, 78, 80, 82, 83, 85, 86, 87, 90, 91, 93, 94, 96, 97, 101, 102, 103, 105, 106, 107, 108, 109, 110, 112, 115, 119, 125, 126

Offset

1,1

Comments

Because 257 is a Fermat prime, these numbers are all primitive roots (mod 257). Complement of A136803.

Links

Nathaniel Johnston, Table of n, a(n) for n = 1..128 (full sequence)

Index entries for sequences related to squares

Formula

a(n) + a(129-n) = 257.

Maple

A136804 := {$(0..256)}: for n from 0 to 256 do A136804 := A136804 minus {n^2 mod 257}: od: op(sort(convert(A136804, list))); # Nathaniel Johnston, Jun 23 2011

Mathematica

p=257; Select[Range[0, p-1], JacobiSymbol[ #, p]==-1&]

Prog

(PARI) for (n=0, 256, if (! issquare(Mod(n, 257)), print1(n, ", "))) \\ Michel Marcus, Mar 12 2017
(PARI) A136804=setminus(S=[0..256], Set([k^2 | k <- S]%257)); \\ M. F. Hasler, Nov 15 2017

Crossrefs

Cf. A136803 (squares mod 257), A136805 and A136806 (squares/nonsquares mod 65537).

Sequence in context: A028811 A034035 A335911 * A129802 A023854 A324511

Adjacent sequences: A136801 A136802 A136803 * A136805 A136806 A136807

Keyword

fini,full,easy,nonn

Author

T. D. Noe, Jan 22 2008

Status

approved