%N Primes arising as the arithmetic mean of a pair of successive terms of A086519.
%C Second term onwards every prime == 1 (mod 6).
%C Conjecture: every prime of the type 6k+1 is a member. Comment from _Vim Wenders_, May 27 2008: The conjecture is worng. For example 19 is missing..
%F a(n) = (A086519(n)+A086519(n+1))/2. - _David Wasserman_, Mar 11 2005
%Y Cf. A086519.
%A _Amarnath Murthy_, Jul 30 2003
%E Corrected and extended by _David Wasserman_, Mar 11 2005