OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
EXAMPLE
For n=18, 11*18-1=197 and 11*18+1=199
MATHEMATICA
Select[Range[3000], PrimeQ[11 # - 1]&& PrimeQ[11 # + 1]&] (* Vincenzo Librandi, Apr 05 2013 *)
PROG
(Magma) [n: n in [1..3000] | IsPrime(11*n+1) and IsPrime(11*n-1)]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Mar 08 2010
STATUS
approved