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

1,1

Comments

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

Links

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

Example

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

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]);

Prog

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

Crossrefs

Cf. A023201, A023203, A318996.

Sequence in context: A164276 A154967 A271211 * A374122 A072381 A046415

Adjacent sequences: A341041 A341042 A341043 * A341045 A341046 A341047

Keyword

nonn

Author

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

Status

approved