Sequential.fsx

let x =
    [| 1 .. 10 |]
    |> Array.map(fun n -> async {
        printfn "Starting %d" n
        do! Async.Sleep 1000
        printfn "Done %d" n
        return n * 1000
    })

let x2 = Async.Parallel(x, 1) |> Async.RunSynchronously
let x3 = x |> Async.Sequential |> Async.RunSynchronously

(* both output:

Starting 1
Starting 2
Starting 3
Starting 4
Starting 5
Starting 6
Starting 7
Starting 8
Starting 9
Starting 10
Done 10
Done 2
Done 1
Done 5
Done 7
Done 3
Done 8
Done 6
Done 9
Done 4

*)