A175157 Numbers n such that 19*n-1, 19*n+1 are twin primes.

12, 30, 78, 222, 252, 330, 498, 582, 588, 630, 660, 702, 720, 750, 768, 828, 852, 1020, 1092, 1122, 1188, 1212, 1230, 1332, 1638, 1722, 1728, 1752, 2112, 2142, 2190, 2220, 2232, 2280, 2310, 2562, 2730, 2928, 3072, 3108, 3192, 3198, 3228, 3240, 3270, 3312

Offset

1,1

Comments

All entries are divisible by 6. - Robert Israel, May 14 2014

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

For n=12, 19*12-1=227, 19*12+1=229.

Maple

3*select(t -> isprime(57*t-1) and isprime(57*t+1), [$1..10000]); # Robert Israel, May 14 2014

Mathematica

Select[6*Range[600], And@@PrimeQ[19#+{1, -1}]&] (* Harvey P. Dale, May 28 2014 *)

Prog

(Magma) [n: n in [1..4000] | IsPrime(19*n+1) and IsPrime(19*n-1)]
(PARI) is(n)=isprime(19*n-1) && isprime(19*n+1) \\ Charles R Greathouse IV, May 14 2014

Crossrefs

Sequence in context: A069486 A211117 A301775 * A371075 A286659 A320483

Adjacent sequences: A175154 A175155 A175156 * A175158 A175159 A175160

Keyword

nonn

Author

Vincenzo Librandi, Mar 08 2010

Status

approved