Exponentiation of g.f. for Pell numbers.

Terms

a(0) =0a(1) =1a(2) =2a(3) =8a(4) =32a(5) =159a(6) =882a(7) =5475a(8) =37256a(9) =276004a(10) =2207944a(11) =18949677a(12) =173475876a(13) =1685805913a(14) =17319275430a(15) =187443865596