a(n) = ((9 + sqrt(5))^n + (9 - sqrt(5))^n)/2.

A152261

a(n) = ((9 + sqrt(5))^n + (9 - sqrt(5))^n)/2.

Terms

    a(0) =1a(1) =9a(2) =86a(3) =864a(4) =9016a(5) =96624a(6) =1054016a(7) =11628864a(8) =129214336a(9) =1442064384a(10) =16136869376a(11) =180866755584

External references