A274557 Numbers k such that sigma(k) == 0 (mod k+6).

6, 24, 25, 30, 42, 54, 66, 78, 102, 114, 138, 174, 186, 222, 246, 258, 282, 304, 318, 354, 366, 402, 426, 438, 474, 498, 534, 582, 606, 618, 642, 654, 678, 762, 786, 822, 834, 894, 906, 942, 978, 1002, 1038, 1074, 1086, 1146, 1158, 1182, 1194, 1266, 1338, 1362

Offset

1,1

Links

Seiichi Manyama, Table of n, a(n) for n = 1..10000

Example

sigma(6) mod (6+6) = 12 mod 12 = 0.

Maple

with(numtheory); P:=proc(q, h) local n;  for n from 1 to q do
if n+h>0 then if type(sigma(n)/(n+h), integer) then print(n); fi; fi; od; end: P(10^9, 6);

Mathematica

Select[Range@ 1400, Mod[DivisorSigma[1, #], # + 6] == 0 &] (* Michael De Vlieger, Jul 05 2016 *)

Prog

(PARI) is(n)=sigma(n)%(n+6)==0 \\ Charles R Greathouse IV, Jul 16 2016

Crossrefs

Cf. A000203, A045770, A067702, A088833, A181598, A274551-A274556, A274558-A274566.

Sequence in context: A203984 A237836 A231324 * A072710 A349688 A273124

Adjacent sequences: A274554 A274555 A274556 * A274558 A274559 A274560

Keyword

nonn

Author

Paolo P. Lava, Jul 05 2016

Status

approved