OFFSET
1,1
COMMENTS
Primes p such that 3*p+2, 9*p+8, 27*p+26, and 81*p+80 are also primes. - Vincenzo Librandi, Aug 04 2010
LINKS
John Cerkan, Table of n, a(n) for n = 1..10000
FORMULA
a(n) == 9 or 69 (mod 70). - John Cerkan, Oct 04 2016
MATHEMATICA
Select[Prime[Range[50000]], AllTrue[Rest[NestList[3#+2&, #, 4]], PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Oct 13 2015 *)
PROG
(Magma) [n: n in [1..1000000] | IsPrime(n) and IsPrime(3*n+2) and IsPrime(9*n+8) and IsPrime(27*n+26) and IsPrime(81*n+80)] // Vincenzo Librandi, Aug 04 2010
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved