A341045 Numbers k such that k divides A318996(k).

1, 4, 6, 28, 45, 120, 496, 672, 6048, 8128, 14421, 30240, 32760, 523776, 2178540, 23569920, 26409026, 29270772, 30685402, 33550336, 45532800

Offset: 1

Author

J. M. Bergot and Robert Israel, Feb 03 2021

Keywords

• nonn
• more

Examples

			a(2) = 4 is a term because A318996(4) = 4 is divisible by 4.
a(3) = 6 is a term because A318996(6) = 0 is divisible by 6.
		

Crossrefs

Contains A007691.

Cf. A318996.

Programs

Maple

f:= proc(n) local s,D,t;
  D:= numtheory:-divisors(n);
  s:= convert(D,`+`);
  add(s mod t, t=D)
end proc:
select(t -> f(t) mod t = 0, [$1..20000]);

PARI

f(n) = my(sn = sigma(n)); sumdiv(n, d, sn % d); \\ A318996
isok(k) = !(f(k) % k); \\ Michel Marcus, Feb 03 2021