OFFSET
1,2
MATHEMATICA
pnQ[n_]:=Module[{pn=Prime[n]}, And@@PrimeQ[{2pn-1, 6pn-1}]]; Select[ Range[ 2000], pnQ] (* Harvey P. Dale, Jan 14 2012 *)
CROSSREFS
KEYWORD
nonn,easy,less
AUTHOR
Juri-Stepan Gerasimov, Feb 06 2010
EXTENSIONS
Corrected and extended by Charles R Greathouse IV, Mar 25 2010
STATUS
approved