a(1) = 4; a(n) is greatest semiprime < a(n-1)^2.

A118908

a(1) = 4; a(n) is greatest semiprime < a(n-1)^2.

Terms

    a(0) =4a(1) =15a(2) =221a(3) =48839a(4) =2385247913

External references