a(1) = prime(1), a(2) = prime(prime( a(1) )), a(3) = prime(prime(prime( a(2) ))), a(4) = prime(prime(prime(prime( a(3) )))), etc.

A092922

a(1) = prime(1), a(2) = prime(prime( a(1) )), a(3) = prime(prime(prime( a(2) ))), a(4) = prime(prime(prime(prime( a(3) )))), etc.

Terms

    a(0) =2a(1) =5a(2) =127a(3) =648391

External references