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A274563 Numbers k such that sigma(k) == 0 (mod k+9). 2
15, 208, 6976, 8415, 31815, 351351, 2077696, 20487159, 159030135, 536559616, 2586415095, 137433972736, 2199003332608 (list; graph; refs; listen; history; text; internal format)
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 * A028230 A122572 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

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Last modified May 19 12:20 EDT 2022. Contains 353833 sequences. (Running on oeis4.)