a(n) = Fibonacci(4n+3) + 2, or Fibonacci(2n+3)*Lucas(2n).

A081011

a(n) = Fibonacci(4n+3) + 2, or Fibonacci(2n+3)*Lucas(2n).

Terms

    a(0) =4a(1) =15a(2) =91a(3) =612a(4) =4183a(5) =28659a(6) =196420a(7) =1346271a(8) =9227467a(9) =63245988a(10) =433494439a(11) =2971215075a(12) =20365011076a(13) =139583862447a(14) =956722026043

External references