%I

%S 7,11,11,11,11,11,11,11,29614931,29614931,1172182334669,

%T 67667595358511,124204021800149

%N Initial prime, greater than 5, of a prime chain of length n under the iteration x->2x-5.

%e a(3) = 11 because 11 11*2-5=17 and 17*2-5=29 are primes.

%Y Cf. A084954.

%K nonn,more

%O 1,1

%A _Don Reble_, Nov 07 2007