OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
EXAMPLE
For p=2, (5,7,11 prime); p=3, (11,13,17 prime); p=19, (107,109,113);
MAPLE
a := proc (n) if isprime(6*ithprime(n)-7) = true and isprime(6*ithprime(n)-5) = true and isprime(6*ithprime(n)-1) = true then ithprime(n) else end if end proc: seq(a(n), n = 1 .. 2200); # Emeric Deutsch, Mar 01 2009
MATHEMATICA
Select[Prime@Range@20000, PrimeQ[6 # - 1] && PrimeQ[6 # - 7] && PrimeQ[6 # - 5] &] (* Vincenzo Librandi, Sep 11 2013 *)
Select[Prime[Range[2200]], AllTrue[6#-{1, 5, 7}, PrimeQ]&] (* Harvey P. Dale, Mar 04 2022 *)
PROG
(Magma) [p: p in PrimesUpTo(20000) | IsPrime(6*p-7) and IsPrime(6*p-5) and IsPrime(6*p-1)]; // Vincenzo Librandi, Sep 11 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Feb 22 2009
EXTENSIONS
Corrected (269 added) and extended by Emeric Deutsch, Mar 01 2009
STATUS
approved