a(n) = ((4+sqrt(2))*(5+sqrt(2))^n + (4-sqrt(2))*(5-sqrt(2))^n)/4.

A161947

a(n) = ((4+sqrt(2))*(5+sqrt(2))^n + (4-sqrt(2))*(5-sqrt(2))^n)/4.

Terms

    a(0) =2a(1) =11a(2) =64a(3) =387a(4) =2398a(5) =15079a(6) =95636a(7) =609543a(8) =3895802a(9) =24938531a(10) =159781864a(11) =1024232427a(12) =6567341398a(13) =42116068159a(14) =270111829436

External references