A153400 -id:A153400 - cp's OEIS frontend

A165810 Primes p such that 18*p+1 is also a prime.

2, 7, 11, 17, 29, 41, 59, 71, 79, 97, 127, 137, 139, 149, 151, 181, 197, 199, 241, 251, 277, 281, 307, 337, 347, 367, 379, 401, 431, 479, 491, 541, 569, 587, 659, 701, 709, 757, 797, 809, 821, 827, 829, 857, 877, 881, 947, 991, 1021, 1051, 1109, 1117, 1129, 1151, 1229

Offset: 1

Vincenzo Librandi, Sep 28 2009

			For p=2, 18*p+1=37. For p=7, 18*p+1=127. For p=11, 18*p+1=199.

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Cf. A111094, A153400, A165811.

Select[Prime[Range[1000]],PrimeQ[18#+1]&]  (* Harvey P. Dale, Mar 06 2011 *)

a(n) = (A165811(n)-1)/18.

Extended by R. J. Mathar, Oct 16 2009

A165811 Primes of the form 18*p+1, where p is also a prime.

Original entry on oeis.org

37, 127, 199, 307, 523, 739, 1063, 1279, 1423, 1747, 2287, 2467, 2503, 2683, 2719, 3259, 3547, 3583, 4339, 4519, 4987, 5059, 5527, 6067, 6247, 6607, 6823, 7219, 7759, 8623, 8839, 9739, 10243, 10567, 11863, 12619, 12763, 13627, 14347, 14563, 14779, 14887

Offset: 1

Vincenzo Librandi, Sep 28 2009

			p=2 contributes 37=18*2+1. p=7 contributes 127=18*7+1. p=11 contributes 199=18*11+1

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Cf. A111094, A153400, A165810.

[a: p in PrimesInInterval(2, 1000) | IsPrime(a) where a is 18*p + 1]; // Vincenzo Librandi, Oct 13 2012

Select[Table[18p + 1, {p, Prime[Range[400]]}], PrimeQ] (* Vincenzo Librandi, Oct 13 2012 *)

a(n) = 1+18*A165810(n).

Extended by R. J. Mathar, Oct 16 2009

cp's OEIS Frontend

A165810 Primes p such that 18*p+1 is also a prime.

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