A037046 - OEIS

A037046

Numbers that are not the number of quadratic residues mod n for any n.

5, 13, 17, 25, 26, 29, 35, 39, 41, 43, 47, 50, 58, 59, 61, 65, 67, 71, 73, 78, 83, 85, 86, 89, 94, 95, 101, 103, 107, 109, 113, 116, 118, 119, 122, 123, 125, 127, 130, 131, 134, 143, 145, 146, 149, 155, 163, 167, 170, 173, 178, 179, 181, 183, 185, 188, 191, 193

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Complement of A037041. - Michel Marcus, Nov 11 2015

LINKS

Table of n, a(n) for n=1..58.

MATHEMATICA

s = Length[Union@ #] & /@ Table[Mod[k^2, n], {n, 10000}, {k, 0, n - 1}]; Complement[Range@ Max@ #, #] &@ Take[Union@ s, 136] (* Michael De Vlieger, Nov 10 2015 *)

CROSSREFS

Cf. A000224, A096008, A111986 (number of numbers having n quadratic residues), A111987 (least number having n quadratic residues), A111988 (greatest number having n quadratic residues).

Sequence in context: A087895 A092101 A105596 * A126887 A339952 A087445

Adjacent sequences: A037043 A037044 A037045 * A037047 A037048 A037049

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved