FizzBuzz

FizzBuzz.cs

public IEnumerable<string> GetFizzBuzz(int max)
{
    var result = new List<string>();

    for (int number = 1; number <= max; number++)
    {
        if (number % 15 == 0)
        {
            result.Add("fizzbuzz");
        }
        else if (number % 3 == 0)
        {
            result.Add("fizz");
        }
        else if (number % 5 == 0)
        {
            result.Add("buzz");
        }
        else
        { 
            result.Add(number.ToString());
        }
    }

    return result;
}

FizzBuzz.fs

// sequence where every third is fizz
let fizzes = cycle [""; ""; "fizz"]

// sequence where every fifth is buzz
let buzzes = cycle [""; ""; ""; ""; "buzz"]

// combined sequence of fizzes and buzzes
let words = Seq.map2 (+) fizzes buzzes

// sequence of numbers starting with "1"
let numbers = Seq.initInfinite show |> Seq.skip 1

// pick the largest string
let choice = max

// combined words and numbers, pick the largest string
let fizzbuzz = Seq.zip words numbers |> Seq.map choice