A048797 Primes p such that pp'-2 is prime, where p' denotes the next prime after p.

3, 157, 211, 257, 367, 557, 977, 997, 1381, 1511, 1531, 2467, 2503, 2621, 2777, 2861, 3049, 3307, 3617, 4099, 4357, 4373, 4397, 4463, 4523, 4691, 4831, 4919, 5087, 5209, 5261, 5351, 5407, 5483, 5807, 6173, 6229, 6287, 6619, 6871, 7001, 7187, 7459, 7577

Offset: 1

Author

Joseph L. Pe, Jan 15 2002

Keywords

• nonn

Examples

			3*5 - 2 = 13, a prime, so 3 is a term of the sequence.
		

Links

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

Crossrefs

Cf. A123921, A124669.

Programs

Mathematica

Prime[ Select[ Range[1000], PrimeQ[ Prime[ # ]Prime[ # + 1] - 2] &]]
Select[Prime[Range[1000]],PrimeQ[# NextPrime[#]-2]&] (* Harvey P. Dale, Aug 05 2024 *)

PARI

lista(nn) = {my(p=2); forprime(q=3, nn, if (isprime(p*q-2), print1(p, ", ")); p = q;);} \\ Michel Marcus, Sep 28 2019