a(n) = ((2+sqrt(5))*(3+sqrt(5))^n + (2-sqrt(5))*(3-sqrt(5))^n)/2.

A162771

a(n) = ((2+sqrt(5))*(3+sqrt(5))^n + (2-sqrt(5))*(3-sqrt(5))^n)/2.

Terms

    a(0) =2a(1) =11a(2) =58a(3) =304a(4) =1592a(5) =8336a(6) =43648a(7) =228544a(8) =1196672a(9) =6265856a(10) =32808448a(11) =171787264a(12) =899489792a(13) =4709789696a(14) =24660779008a(15) =129125515264a(16) =676109975552

External references