a(0) = 1, a(n) is the greatest prime factor of a(n-1)^2+1 for n > 0.

A031439

a(0) = 1, a(n) is the greatest prime factor of a(n-1)^2+1 for n > 0.

Terms

    a(0) =1a(1) =2a(2) =5a(3) =13a(4) =17a(5) =29a(6) =421a(7) =401a(8) =53a(9) =281a(10) =3037a(11) =70949a(12) =1713329

External references