Puzzle solver triangle ( A = diff of b&c )

Program.cs

using System;

class Program
{
    private static int a = 5,
                       b = 9,
                       c = 4,
                       d = 1,
                       e = 1,
                       f = 1,
                       g = 1,
                       h = 1,
                       i = 1,
                       j = 1,
                       k = 1,
                       l = 1,
                       m = 1,
                       n = 1,
                       o = 1;

    private static void Main(string[] args)
    {
        string s1 = "    {0}";
        string s2 = "   {0} {1}";
        string s3 = "  {0} {1} {2}";
        string s4 = " {0} {1} {2} {3}";
        string s5 = "{0} {1} {2} {3} {4}";
        for (; d < 16; d++)
            for (; e < 16; e++)
                for (; f < 16; f++)
                    for (; g < 16; g++)
                        for (; h < 16; h++)
                            for (; i < 16; i++)
                                for (; j < 16; j++)
                                    for (; k < 16; k++)
                                        for (; l < 16; l++)
                                            for (; m < 16; m++)
                                                for (; n < 16; n++)
                                                    for (; o < 16; o++)
                                                        if (Check())
                                                        {
                                                            Console.WriteLine("Found it!");
                                                            Console.WriteLine(s1, a);
                                                            Console.WriteLine(s2, b, c);
                                                            Console.WriteLine(s3, d, e, f);
                                                            Console.WriteLine(s4, g, h, i, j);
                                                            Console.WriteLine(s5, k, l, m, n, o);
                                                            Console.ReadKey(true);
                                                            return;
                                                        }
        Console.WriteLine("No answer!");
        Console.ReadKey(true);
    }

    private static bool Check()
    {
        if (Math.Abs(d - e) != b) return false;
        if (Math.Abs(e - f) != c) return false;
        if (Math.Abs(g - h) != d) return false;
        if (Math.Abs(h - i) != e) return false;
        if (Math.Abs(i - j) != f) return false;
        if (Math.Abs(k - l) != g) return false;
        if (Math.Abs(l - m) != h) return false;
        if (Math.Abs(m - n) != i) return false;
        if (Math.Abs(n - o) != j) return false;
        return true;
    }
}