OFFSET
1,3
COMMENTS
a(11) > 2*10^5. - Robert Price, Oct 16 2015
MATHEMATICA
Join[{0}, Select[Range[1, 175, 2], PrimeQ[2*11^# + 1] &]] (* Arkadiusz Wesolowski, Nov 06 2012 *)
PROG
(PARI) for(n=0, 1e5, if(isprime(2*11^n + 1), print1(n", "))) \\ Altug Alkan, Oct 16 2015
CROSSREFS
KEYWORD
hard,nonn
AUTHOR
Rick L. Shepherd, Jul 03 2008
EXTENSIONS
a(8)-a(10) from Arkadiusz Wesolowski, Nov 06 2012
STATUS
approved