module Seq =
  let rec repeat items =
    seq { yield! items
          yield! repeat items }

let fizzes   = Seq.repeat [""; ""; "Fizz"]
let buzzes   = Seq.repeat [""; ""; ""; ""; "Buzz"]
let words    = Seq.map2 (+) fizzes buzzes
let numbers  = Seq.initInfinite ((+) 1) |> Seq.map string
let fizzBuzz = Seq.map2 max words numbers

fizzBuzz
|> Seq.take 100
|> Seq.iter (printfn "%s")