a(n) = (1/(10*sqrt(2)))*((1 + sqrt(2))^(3^n) - (1 - sqrt(2))^(3^n)).

A145452

a(n) = (1/(10*sqrt(2)))*((1 + sqrt(2))^(3^n) - (1 - sqrt(2))^(3^n)).

Terms

    a(0) =1a(1) =197a(2) =1529074009

External references