A274566 Numbers k such that sigma(k) == 0 (mod k-10).

11, 12, 14, 22, 40, 42, 46, 154, 190, 2656, 6490, 44650, 318250, 1360810, 1503370, 1788490, 3214090, 103712410, 3915380170, 6077111050, 9796360330, 10828121356, 33086522327050, 35966517350410

Offset

1,1

Links

Table of n, a(n) for n=1..24.

Example

sigma(11) mod (11 - 10) = 12 mod 1 = 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, -10);

Mathematica

k=-10; Select[Range[Abs@k+1, 10^7], Mod[DivisorSigma[1, #], #+k] == 0 &] (* Vincenzo Librandi, Jul 06 2016 *)

Prog

(Magma) [n: n in [11..2*10^6] | SumOfDivisors(n) mod (n-10) eq 0 ]; // Vincenzo Librandi, Jul 06 2016

Crossrefs

Cf. A045770, A067702, A088833, A181598, A223607, A274551-A274565.

Sequence in context: A034907 A045987 A121978 * A349153 A213309 A128997

Adjacent sequences: A274563 A274564 A274565 * A274567 A274568 A274569

Keyword

nonn,more

Author

Paolo P. Lava, Jul 06 2016

Extensions

a(17)-a(22) from Giovanni Resta, Jul 06 2016

a(23)-a(24) from Jud McCranie, Dec 02 2019

Status

approved