A274563 Numbers k such that sigma(k) == 0 (mod k+9).

15, 208, 6976, 8415, 31815, 351351, 2077696, 20487159, 159030135, 536559616, 2586415095, 137433972736, 2199003332608

Offset

1,1

Links

Table of n, a(n) for n=1..13.

Example

sigma(15) mod (15 + 9) = 24 mod 24 = 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, 9);

Mathematica

Select[Range[10^6], Mod[DivisorSigma[1, #], # + 9] == 0 &] (* Michael De Vlieger, Jul 06 2016 *)

Crossrefs

Cf. A045770, A067702, A088833, A181598, A223610, A274551-A274562, A274564-A274566.

Sequence in context: A051813 A280160 A239991 * A122572 A028230 A067560

Adjacent sequences: A274560 A274561 A274562 * A274564 A274565 A274566

Keyword

nonn,more

Author

Paolo P. Lava, Jul 06 2016

Extensions

a(7)-a(13) from Giovanni Resta, Jul 06 2016

Status

approved