A054017 Chowla's function of n modulo n is a square (excluding 0's).

14, 20, 39, 40, 46, 55, 80, 94, 100, 104, 117, 130, 155, 158, 183, 190, 200, 203, 291, 292, 295, 299, 320, 323, 334, 416, 430, 446, 464, 475, 488, 530, 539, 549, 567, 579, 583, 638, 650, 695, 718, 799, 873, 878, 890, 943, 955, 959, 964, 979, 1030, 1118

Offset

1,1

Comments

Chowla's function (A048050) = sum of divisors of n except 1 and n.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Mathematica

aQ[n_] := (c = DivisorSigma[1, n] - n - 1) > 0 && IntegerQ @ Sqrt @ Mod[c, n]; Select[Range[1000], aQ] (* Amiram Eldar, Aug 28 2019 *)

Crossrefs

Cf. A048050, A054013, A054018.

Sequence in context: A108874 A063848 A110968 * A129216 A259536 A067796

Adjacent sequences: A054014 A054015 A054016 * A054018 A054019 A054020

Keyword

nonn

Author

Asher Auel, Jan 19 2000

Status

approved