OFFSET
1,1
EXAMPLE
sigma(9) mod 9+4 = 13 mod 13 = 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, 4);
MATHEMATICA
k = 4; Select[Range[Abs@ k + 1, 10^6], Mod[DivisorSigma[1, #], # + k] == 0 &] (* Michael De Vlieger, Jul 01 2016 *)
PROG
(Magma) [n: n in [1..2*10^6] | SumOfDivisors(n) mod (n+4) eq 0 ]; // Vincenzo Librandi, Jul 02 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Paolo P. Lava, Jun 28 2016
EXTENSIONS
a(18)-a(35) from Giovanni Resta
STATUS
approved