a(1) = 2. For n > 1, a(n) = 2*a(n-1) + p for the least prime p > 2*a(n-1) such that 2*a(n-1) + p is prime.

A355974

a(1) = 2. For n > 1, a(n) = 2*a(n-1) + p for the least prime p > 2*a(n-1) such that 2*a(n-1) + p is prime.

Terms

    a(0) =2a(1) =11a(2) =53a(3) =233a(4) =953a(5) =3917a(6) =15761a(7) =63149a(8) =252731a(9) =1011221a(10) =4045091a(11) =16180391a(12) =64721819a(13) =258887357a(14) =1035549707a(15) =4142198861a(16) =16568795489a(17) =66275182097a(18) =265100728391

External references