A067463 Primes p such that p+sigma(p+1) is prime.

5, 13, 19, 23, 29, 37, 41, 43, 53, 59, 61, 67, 83, 101, 103, 113, 131, 149, 157, 163, 167, 193, 223, 227, 229, 239, 263, 271, 281, 283, 293, 311, 313, 331, 347, 349, 373, 397, 401, 433, 461, 467, 491, 503, 523, 563, 571, 599, 601, 607, 631, 643, 653, 661, 683

Offset: 1

Author

Benoit Cloitre, Feb 23 2002

Keywords

• easy
• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A008333, A067464.

Programs

Mathematica

Select[Prime[Range[124]], PrimeQ[# + DivisorSigma[1, #+1]] &] (* Amiram Eldar, Apr 24 2025 *)

PARI

isok(p) = isprime(p) && isprime(p+sigma(p+1)); \\ Michel Marcus, Feb 17 2021