let test t =
    let a,b,c = t
    (a < b) && (b < c) && (a + b + c = 1000) && (a * a + b * b = c * c)

let generator t =
    let x,y = t
    let x2 = x * x
    let y2 = y * y
    let a = 2 * x * y
    let b = x2 - y2
    let c = x2 + y2
    a,b,c

let c n =
    [1..(n-1)]
    |> List.chunkBySize 1
    |> List.map (fun x -> n,(List.item 0 x))

let result =
    [1..20]
    |> List.map c
    |> List.concat
    |> List.map (fun x -> (
        generator x
    ))
    |> List.filter (fun x -> (
        test x
    ))