A074630 Numbers k such that sigma(k) == 4 mod 6.

3, 12, 27, 48, 75, 91, 108, 133, 192, 217, 243, 247, 259, 273, 300, 301, 343, 363, 364, 399, 403, 427, 432, 469, 481, 511, 532, 553, 559, 589, 651, 675, 679, 703, 721, 741, 763, 768, 777, 793, 817, 819, 867, 868, 871, 889, 903, 949, 972, 973, 988, 1027, 1029

Offset: 1

Author

Labos Elemer, Aug 26 2002

Keywords

• easy
• nonn

Examples

			k=48 is a term because sigma(48) = 1+2+3+4+6+8+12+16+24+48 = 124 = 6*20 + 4. [corrected by _Harvey P. Dale_, Jan 17 2013]
		

Links

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

Crossrefs

Cf. A000203, A067051, A072862, A074384, A074627, A074628.

Programs

Mathematica

Select[Range[1100],Mod[DivisorSigma[1,#],6]==4&] (* Harvey P. Dale, Jan 17 2013 *)

Formula

Mod(A000203(n), 6) = 4.

{n: A084301(n) = 4}. - R. J. Mathar, May 19 2020