a(n) = ((4+sqrt(5))*(3+sqrt(5))^n + (4-sqrt(5))*(3-sqrt(5))^n)/2.

A163071

a(n) = ((4+sqrt(5))*(3+sqrt(5))^n + (4-sqrt(5))*(3-sqrt(5))^n)/2.

Terms

    a(0) =4a(1) =17a(2) =86a(3) =448a(4) =2344a(5) =12272a(6) =64256a(7) =336448a(8) =1761664a(9) =9224192a(10) =48298496a(11) =252894208a(12) =1324171264a(13) =6933450752a(14) =36304019456a(15) =190090313728a(16) =995325804544

External references