a(n) = ((9+sqrt(9))^n + (9-sqrt(9))^n)/2.
A143079
a(n) = ((9+sqrt(9))^n + (9-sqrt(9))^n)/2.
Terms
- a(0) =1a(1) =9a(2) =90a(3) =972a(4) =11016a(5) =128304a(6) =1516320a(7) =18055872a(8) =215830656a(9) =2584929024a(10) =30988915200a(11) =371685583872
External references
- oeis: A143079