MonkeysAndCoconuts.fs

let sailorDivide pile = 
    let monkeyShare = 1
    let preDividePile = pile - monkeyShare
    let sailorShare = preDividePile / 5
    if not (sailorShare * 5 = preDividePile) then -1
    else preDividePile - sailorShare
let groupDivide pile = 
    let sailorShare = pile / 5
    if not (sailorShare * 5 = pile) then -1
    else 0
let testSum pile = 
    let result = pile |> sailorDivide |> sailorDivide |> sailorDivide |> sailorDivide |> sailorDivide |> groupDivide
    result >= 0
let solutions = seq {
    let i = ref 0
    while true do
        i := i.Value + 1
        if testSum i.Value then
            yield i.Value
}

[<EntryPoint>]
let main argv = 
    let list = 
        solutions
        |> Seq.take 10
        |> Seq.toList

    printfn "%A" list
    0