A122905 Numbers m such that in Z/mZ the number of squares is strictly greater than the number of invertible elements.

2, 6, 10, 14, 18, 22, 26, 30, 34, 38, 42, 46, 50, 54, 58, 62, 66, 74, 78, 82, 86, 94, 98, 102, 106, 114, 118, 122, 134, 138, 142, 146, 150, 158, 162, 166, 174, 178, 186, 194, 202, 206, 214, 218, 222, 226, 242, 246, 250, 254, 258, 262, 274, 278, 282, 294, 298, 302

Offset

1,1

Comments

Numbers m such that A000224(m) > A000010(m).

Links

Ivan Neretin, Table of n, a(n) for n = 1..10000

Mathematica

Select[Range@310, Length@Union@Mod[Range[#]^2, #] > EulerPhi[#] &] (* Ivan Neretin, Dec 14 2016 *)
f1[p_, e_] := Floor[p^(e+1)/(2p + 2)] + 1; f1[2, e_] := Floor[2^e/6] + 2; f[p_, e_] := f1[p, e]/((p-1) * p^(e-1)); q[1] = False; q[k_] := Times @@ f @@@ FactorInteger[k] > 1; Select[Range[300], q] (* Amiram Eldar, Nov 11 2024 *)

Crossrefs

Complement of A122906 in positive integers.

Cf. A000010, A000224, A122903, A122904, A122907.

Sequence in context: A130824 A016825 A161718 * A132417 A103747 A333662

Adjacent sequences: A122902 A122903 A122904 * A122906 A122907 A122908

Keyword

nonn

Author

Max Alekseyev, Sep 18 2006

Status

approved