iterator block gotcha sample code - F# equivalent

program.fs

// Learn more about F# at http://fsharp.net
open System

let showMemory( msg : string) =
    let memory = GC.GetTotalMemory(true)
    Console.WriteLine("{0, -30} {1}", msg + ":", memory)

let main ()= 
    let source = seq {0 .. 1000000}
    let query = Seq.distinct source
    
    showMemory("Before Count()")
    Seq.length query |> ignore
    showMemory("After Count()")
    GC.KeepAlive(query)
    showMemory("After query eligible for GC")

main()