%I A137288
%S A137288 1,2,4,8,11,12,22,25,34,37,46,47,50,58,63,67,68,73,75,85,95,101,106,110,
%T A137288 111,114,121,125,129,141,145,151,159,163,168,169,180,193,203,207,211,
%U A137288 222,226,232,242,254,258,260,274,285
%N A137288 Numbers n such that 2*p(n)-1 is prime, where p(n) is the n-th prime.
%e A137288 n=11 : 2*p(11)-1 = 2* 31-1 = 61 is prime, n=11 belongs to the sequence.
%p A137288 P:=proc(n) local a,i; for i from 1 by 1 to n do a:=2*ithprime(i)-1; if 
               isprime(a) then print(i); fi; od; end: P(301); - Paolo P. Lava (ppl(AT)spl.at), 
               Apr 15 2008
%Y A137288 Cf. A000040.
%Y A137288 Sequence in context: A028846 A080152 A136994 this_sequence A116443 A078649 
               A161607
%Y A137288 Adjacent sequences: A137285 A137286 A137287 this_sequence A137289 A137290 
               A137291
%K A137288 easy,nonn
%O A137288 1,2
%A A137288 Ctibor O. Zizka (ctibor.zizka(AT)seznam.cz), Apr 05 2008
%E A137288 More terms from Paolo P. Lava (ppl(AT)spl.at), Apr 15 2008