FizzBuzz without conditionals.

Program.cs

namespace FizzBuzzEnumerable;

using System.Collections;
using System.Collections.Generic;

class Program
{
    public class FizzBuzzEnumerable : IEnumerable<string>
    {
        public IEnumerator<string> GetEnumerator()
        {
            int n = 0;
            Loop:
            yield return (n + 1).ToString();
            yield return (n + 2).ToString();
            yield return "Fizz";
            yield return (n + 4).ToString();
            yield return "Buzz";
            yield return "Fizz";
            yield return (n + 7).ToString();
            yield return (n + 8).ToString();
            yield return "Fizz";
            yield return "Buzz";
            yield return (n + 11).ToString();
            yield return "Fizz";
            yield return (n + 13).ToString();
            yield return (n + 14).ToString();
            yield return "Fizz Buzz";
            n += 15;
            goto Loop;
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }
    }

    static void Main(string[] args)
    {
        foreach (var s in new FizzBuzzEnumerable().Take(int.Parse(args[0]))) 
        {
            Console.WriteLine(s);
        }
    }
}