Data commit

Task/Fibonacci-n-step-number-sequences/F-Sharp/fibonacci-n-step-number-sequences.fs

@@ -0,0 +1,24 @@
+let fibinit = Seq.append (Seq.singleton 1) (Seq.unfold (fun n -> Some(n, 2*n)) 1)
+
+let fiblike init =
+    Seq.append
+        (Seq.ofList init)
+        (Seq.unfold
+            (function   | least :: rest ->
+                            let this = least + Seq.reduce (+) rest
+                            Some(this, rest @ [this])
+                        | _ -> None) init)
+
+let lucas = fiblike [2; 1]
+
+let nacci n = Seq.take n fibinit |> Seq.toList |> fiblike
+
+[<EntryPoint>]
+let main argv =
+    let start s = Seq.take 15 s |> Seq.toList
+    let prefix = "fibo tribo tetra penta hexa hepta octo nona deca".Split()
+    Seq.iter
+        (fun (p, n) -> printfn "n=%2i, %5snacci -> %A" n p (start (nacci n)))
+        (Seq.init prefix.Length (fun i -> (prefix.[i], i+2)))
+    printfn "      lucas      -> %A" (start (fiblike [2; 1]))
+    0