A166985 - OEIS

%I #3 Mar 30 2012 18:52:34

%S 2,3,2,3,2,5,2,3,3,5,11,11,23,29,41,23,53,29,41,83,89,53,113,131,83,

%T 173,89,179,191,113,233,239,251,131,281,293,173,179,359,191,419,431,

%U 443,233,239,491,251,509,281,293,593,641,653,659,683,359,719,743,761,809,419

%N Primes of the form phi(n)/2.

%e a(1)=2 (=phi(5)/2); a(2)=3 (=phi(7)/2); a(3)=2 (=phi(8)/2); a(4)=3 (=phi(9)/2); a(5)=2 (=phi(10)/2); a(6)=5 (=phi(11)/2).

%Y Cf. A000010, A000040.

%Y Cf. A005384. [From _R. J. Mathar_, Oct 28 2009]

%K nonn

%O 1,1

%A _Juri-Stepan Gerasimov_, Oct 26 2009

%E Extended by _R. J. Mathar_, Oct 28 2009