Primes in A154117.

Terms

a(0) =2a(1) =7a(2) =17a(3) =37a(4) =157a(5) =317a(6) =1277a(7) =2557a(8) =20477a(9) =655357a(10) =5242877a(11) =671088637a(12) =2684354557a(13) =5368709117a(14) =343597383677