OFFSET
1,1
COMMENTS
Primes p such that 3*p+2, 9*p+8, 27*p+26, 81*p+80 and 243*p+242 are also primes. - Vincenzo Librandi, Aug 04 2010
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..180
MATHEMATICA
p5Q[n_]:=And@@PrimeQ[Rest[NestList[3#+2&, n, 5]]]; Select[ Prime[ Range[ 1600000]], p5Q] (* Harvey P. Dale, May 02 2011 *)
PROG
(Magma) [p: p in PrimesUpTo(25*10^6) | forall{k: k in [1..5] | IsPrime((p+1)*3^k-1)}]; // Bruno Berselli, May 03 2011
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved