G.f.: exp( Sum_{n>=1} 2*Pell(n)^(2*n) * x^n/n ), where Pell(n) = A000129(n).

A208056

G.f.: exp( Sum_{n>=1} 2*Pell(n)^(2*n) * x^n/n ), where Pell(n) = A000129(n).

Terms

    a(0) =1a(1) =2a(2) =18a(3) =10450a(4) =215011842

External references