A023214 Primes p such that 4*p + 5 is also prime.

2, 3, 17, 23, 47, 59, 83, 101, 107, 113, 149, 167, 191, 233, 251, 257, 281, 311, 401, 443, 449, 467, 503, 521, 569, 593, 617, 647, 653, 677, 761, 827, 839, 857, 863, 881, 941, 947, 971, 1013, 1031, 1049, 1109, 1163, 1181, 1277, 1301, 1307, 1319, 1361, 1409, 1433

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Comments

Except for the first two terms, all terms are congruent to 5 (mod 6). - John Cerkan, Sep 07 2016

Links

• John Cerkan, Table of n, a(n) for n = 1..10000

Crossrefs

Subsequence of A111215. - Michel Marcus, Jul 08 2016

Programs

Magma

[n: n in [0..100000] | IsPrime(n) and IsPrime(4*n+5)] // Vincenzo Librandi, Aug 04 2010

Maple

A023214:=n->`if`(isprime(n) and isprime(4*n+5), n, NULL): seq(A023214(n), n=1..3*10^3); # Wesley Ivan Hurt, Sep 07 2016

Mathematica

Select[Prime[Range[250]],PrimeQ[4#+5]&] (* Harvey P. Dale, Oct 21 2018 *)