Not a port scanner

//I AM NOT RESPONSIBLE FOR ANYTHING YOU DO WITH THIS CODE!
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Net.NetworkInformation;
using System.Net;
using System.Net.Sockets;
using System.Runtime.InteropServices;
using System.Threading;
using System.IO;
using System.Windows.Forms;

namespace EffectivePortScan
{
    class Program
    {
        public static List<int> port = new List<int>();
        public static string ip = "";
        public static int portRangeMin = 0;
        public static int portRangeMax = 0;

        static void Main(string[] args)
        {
            Console.Write("IP: ");
            ip = Console.ReadLine();
            Console.Write("Start from port: ");
            portRangeMin = (Convert.ToInt32(Console.ReadLine()) - 1);
            Console.Write("Continue until port: ");
            portRangeMax = Convert.ToInt32(Console.ReadLine());
            Console.Clear();

            for (int i = 0; i < portRangeMax - portRangeMin; i++)
            {
                port.Add(0);
            }

            for (int i = 0; i < portRangeMax - portRangeMin; i++)
            {
                Thread.Sleep(250);
                Task.Run(() => scan(ip + portRangeMin, i));
            }

            Console.WriteLine("Finished with scan, writing to file...");

            Thread.Sleep(2500);
            TextWriter outputStream = new StreamWriter("output.txt", true);

            for (int i = 0; i < port.Count; i++)
            {
                if (port[i] == 0)
                    outputStream.WriteLine((portRangeMin + i) + " : is closed");
                else
                    outputStream.WriteLine((portRangeMin + i) + " : is open");
            }
            outputStream.Close();

            Console.WriteLine("I'm done!");
            Console.ReadLine();
        }

        async static Task scan(string ip, int p)
        {
            try
            {
                TcpClient ports = new TcpClient();
                ports.SendTimeout = 100;
                ports.SendBufferSize = 100;
                ports.Connect(ip, Convert.ToInt32(p));
                Console.WriteLine(p + ": Open");
                port[p] = 1;
            }
            catch
            {
                Console.WriteLine(p + ": Closed");
            }
        }
    }
}