Primes of the form (3^k-1)/2 or (3^k+1)/2.

A088553

Primes of the form (3^k-1)/2 or (3^k+1)/2.

Terms

    a(0) =2a(1) =5a(2) =13a(3) =41a(4) =1093a(5) =797161a(6) =21523361

External references