Unilecs task 126

.fs

open System

let s = Seq.unfold (fun (f, g) -> Some( (f, g), (f + g, f + 2 * g) ) ) (1, 1)

let foo n = 
       let (f_n, g_n) = s |> Seq.take n |> Seq.last 
       printfn "for n = %d the result is %d" n (f_n + 2 * g_n)

[<EntryPoint>]
let main argv = 
    foo 1
    foo 2
    foo 3
    foo 5

    let n = int (System.Console.ReadLine())
    foo n

    System.Console.ReadLine() |> ignore
    0