a(n) = smallest prime p such that the first n iterates of p under x->2x+1 are all primes.

A057331

a(n) = smallest prime p such that the first n iterates of p under x->2x+1 are all primes.

Terms

    a(0) =2a(1) =2a(2) =2a(3) =2a(4) =2a(5) =89a(6) =1122659a(7) =19099919a(8) =85864769a(9) =26089808579a(10) =554688278429a(11) =554688278429

External references