diamond (sample for cs 101)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;

namespace Rextester
{
    public class Program
    {
        public static void Main(string[] args)
        {

            const int MAX = 8;
            const bool CENTERED = true;

            for(int i = 0; i <= MAX; i++)
            {
                string output = "";
                int sequence = sequencify(i, MAX);
                int result = resultify(sequence);


                for(int j = 0; j < result; j++)
                {
                    output += "*";
                }
                if(CENTERED)
                {
                    for(int j = sequence; j < MAX/2; j++)
                    {
                        output = " "+output;
                    }
                }
                Console.WriteLine(output);
            }


            Console.WriteLine($"[index]\t-> [sequence]\t-> [1+sequence*2]");
            for(int i = 0; i < 9; i++)
            {
                Console.WriteLine($"{i}\t->\t {sequencify(i,MAX)}\t->\t {resultify(sequencify(i,MAX))}");
            }

        }
        public static int sequencify(int i, int period)
        {
            //0 1 2 3 4 5 6 7 0
            //0 1 2 3 4 3 2 1 0
            int half = period / 2;
            return i <= half ? i : period - i;
        }
        public static int resultify(int i)
        {
            //0 1 2 3 4 3 2 1 0
            //1 3 5 7 9 7 5 3 1
            return 1 + i * 2;
        }
    }
}