Draw Christmas tree

Write a method that draws Christmas tree shape like below.
Expected input and output
DrawChristmasTree() → * *** ***** ******* * *** ***** ******* * *** ***** *******
using System;

namespace CSharpExercises.Exercises.Loops
{
    class DrawChristmasTreeTask
    {
        static void DrawChristmasTree()
        {
            for (var i = 0; i < 3; i++)
            {
                for (var j = 0; j < 7; j += 2)
                {
                    for (var k = 0; k < (7 - j) / 2; k++)
                    {
                        Console.Write(" ");
                    }
                    for (var m = 0; m <= j; m++)
                    {
                        Console.Write("*");
                    }
                    for (var n = (7 - j) / 2; n < 7; n++)
                    {
                        Console.Write(" ");
                    }
                    Console.WriteLine();
                }
            }
        }

        static void Main(string[] args)
        {
            DrawChristmasTree();
        }
    }
}