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
Keywords
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
Programs
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Mathematica
Prime[ Select[ Range[1000], PrimeQ[ Prime[ # ]Prime[ # + 1] - 2] &]] Select[Prime[Range[1000]],PrimeQ[# NextPrime[#]-2]&] (* Harvey P. Dale, Aug 05 2024 *)
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PARI
lista(nn) = {my(p=2); forprime(q=3, nn, if (isprime(p*q-2), print1(p, ", ")); p = q;);} \\ Michel Marcus, Sep 28 2019