public static void Main()
Console.WriteLine(bin2dec(55));
public static string bin2dec(int number)
if (number == 0) return "0";
var digits = (int) Math.Floor(Math.Log(number, 2)) + 1;
var bin = Enumerable.Repeat<int>(0,digits).ToArray();
var power = (int)Math.Floor(Math.Log(remainder, 2));
remainder = remainder - (int)Math.Pow(2,power);
bin[digits - power - 1] = 1;
return String.Join("",bin);