A341044 Numbers k such that A318996(k) is prime.

8, 9, 10, 14, 15, 21, 22, 25, 26, 33, 34, 39, 42, 46, 57, 62, 65, 66, 69, 72, 74, 76, 80, 82, 87, 91, 92, 93, 94, 95, 100, 106, 111, 116, 119, 121, 122, 129, 133, 134, 145, 146, 159, 162, 166, 172, 176, 177, 183, 184, 190, 194, 202, 203, 206, 208, 213, 214, 215, 219, 232, 236, 237, 238, 240, 243

Offset: 1

Author

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

Keywords

• nonn

Comments

Contains 2*p for p in A023201 and 3*p for p in A023203.

Examples

			a(3) = 10 is a term because A318996(10) = 11 is prime.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A023201, A023203, 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 -> isprime(f(t)), [$1..1000]);

PARI

f(n) = my(sn = sigma(n)); sumdiv(n, d, sn % d); \\ A318996
isok(k) = isprime(f(k)); \\ Michel Marcus, Feb 04 2021