A072462 Numbers k such that sigma(k) == 3 (mod 4).

2, 4, 8, 16, 18, 25, 32, 36, 64, 72, 98, 128, 144, 162, 169, 196, 225, 242, 256, 288, 289, 324, 392, 484, 512, 576, 648, 722, 784, 841, 882, 968, 1024, 1058, 1152, 1225, 1250, 1296, 1369, 1444, 1458, 1521, 1568, 1681, 1764, 1922, 1936, 2025, 2048, 2116, 2178

Offset

1,1

Links

Ray Chandler, Table of n, a(n) for n = 1..10000

Mathematica

Select[Range[2200], Mod[DivisorSigma[1, #], 4] == 3 &] (* Michael De Vlieger, Aug 10 2023 *)

Prog

(PARI) isok(n) = ((sigma(n) % 4) == 3); \\ Michel Marcus, Dec 19 2013

Crossrefs

Cf. A000203, A028982, A072461.

Sequence in context: A331382 A154362 A226221 * A369951 A088827 A316900

Adjacent sequences: A072459 A072460 A072461 * A072463 A072464 A072465

Keyword

nonn

Author

Labos Elemer, Jun 19 2002

Extensions

Name edited by Michel Marcus, Dec 19 2013

Status

approved