Ultra-useful primes: smallest k such that 2^(2^n) - k is prime.
A058220
Ultra-useful primes: smallest k such that 2^(2^n) - k is prime.
Terms
- a(0) =1a(1) =3a(2) =5a(3) =15a(4) =5a(5) =59a(6) =159a(7) =189a(8) =569a(9) =105a(10) =1557a(11) =2549a(12) =2439a(13) =13797a(14) =25353a(15) =5627a(16) =24317a(17) =231425a(18) =164073
External references
- oeis: A058220