A382199 Primes p such that for each digit of p, 2*p*(digit) + 1 is prime.

3, 11, 131, 173, 491, 797, 947, 1931, 3583, 4391, 6173, 7937, 32323, 49919, 64499, 79997, 83383, 149111, 232333, 296269, 366161, 477947, 611333, 616169, 616961, 635563, 667673, 969179, 1111991, 1779779, 2232523, 2662669, 2922229, 3444341, 5333353, 5599999, 6853663, 6919691, 6929929

Offset: 1

Author

Michel Marcus, Mar 18 2025

Keywords

• nonn
• base

Crossrefs

Subsequence of primes of A382179.

Cf. A382127, A382198.

Programs

PARI

isok(k) = if (isprime(k), my(d=Set(digits(k))); for (i=1, #d, if (!isprime(2*k*d[i]+1), return(0))); return(1)); \\ Michel Marcus, Mar 18 2025