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
KEYWORD
nonn
AUTHOR
Vincenzo Librandi, Mar 08 2010
STATUS
approved