A377317 Numbers k such that prime(k), prime(k)+6, and prime(k)+12 are primes.

3, 4, 5, 7, 11, 13, 15, 18, 19, 25, 26, 36, 39, 49, 54, 55, 58, 69, 73, 102, 107, 110, 111, 116, 118, 129, 160, 164, 182, 184, 187, 194, 199, 206, 210, 218, 225, 229, 234, 236, 252, 253, 260, 271, 272, 275, 284, 285, 291, 300, 321, 339, 351, 352, 358, 387, 388

Offset: 1

Author

Kritsada Moomuang, Oct 24 2024

Keywords

• nonn

Examples

			5 is in this sequence because: prime(5) = 11, and 11+6 = 17 and 11+12 = 23 are primes.
		

Crossrefs

Cf. A000040, A000720, A023241.

Supersequence of A377318.

Programs

Mathematica

Select[Range[1, PrimePi[3000]], PrimeQ[Prime[#] + 6] && PrimeQ[Prime[#] + 12] &]

PARI

for(k=1, primepi(3000), p = prime(k); if(isprime(p+6) && isprime(p+12), print(k)))

Formula

a(n) = pi(A023241(n)).