A127430 Primes p such that 6p-5 and 6p+5 are also primes.

2, 3, 7, 11, 13, 17, 31, 41, 59, 71, 73, 97, 113, 139, 157, 193, 239, 269, 277, 311, 337, 349, 421, 449, 487, 577, 587, 619, 643, 701, 811, 823, 827, 941, 977, 1021, 1051, 1093, 1217, 1249, 1259, 1361, 1373, 1471, 1571, 1721, 1723, 1747, 1777, 1789, 1861, 1907

Offset

1,1

Comments

Subsequence of primes p such that 6p-5 and 6p+5 are consecutive primes: 31, 41, 71, 97, 139, 193, 337, 349, 421, 487, 587, 619, 643, 701, 811, 827, 1021, 1051, 1093, 1217, 1249, 1259, 1471, 1571, 1721, 1747, .... - Zak Seidov, Mar 27 2017

Links

Table of n, a(n) for n=1..52.

Example

Example: 11, 6*11+5=71, 6*11-5=61 are all primes.

Maple

A127430:=n->`if`(isprime(n) and isprime(6*n-5) and isprime(6*n+5), n, NULL): seq(A127430(n), n=1..2000); # Wesley Ivan Hurt, Oct 23 2014

Mathematica

Select[Range[5000], PrimeQ[ # ] && PrimeQ[6# + 5] && PrimeQ[6# - 5] &]

Prog

(Magma) [ p: p in PrimesUpTo(9000) | IsPrime(6*p-5) and IsPrime(6*p+5)] // - Vincenzo Librandi, Jan 29 2011
(PARI) is(n)=isprime(n) && isprime(6*n-5) && isprime(6*n+5) \\ Charles R Greathouse IV, Mar 28 2017

Crossrefs

Sequence in context: A296931 A278698 A023221 * A171595 A106483 A145673

Adjacent sequences: A127427 A127428 A127429 * A127431 A127432 A127433

Keyword

nonn

Author

Zerinvary Lajos, Mar 31 2007

Status

approved