
one possible bonus, the hockey stick, is formed in many ways, so long as the numbers add up, like in the image below, where
1 + 12 = 13
1 + 6 + 26 + 56 = 84
1 + 7 + 28 + 84 + 210 + 462 + 924 = 1716

and another bonus, Fibonnacci's numbers (can begin from left side or right side, which is nice)
1, 2
1, 3, 1
1, 4, 3
1 ,5, 6, 1
1, 6, 10, 4
1, 7, 15, 10, 1
etc.

and here is a way to make it even more interesting....3D. note that the yellow and purple coloring corresponds to odd and even numbers, respectively

an alternative appearance of the triangle, also showing odds and evens in different colors. one could easily make a square using 2 triangles with the shape below, which would be effectively the same as the 3D image above.

this could be made either a simple map, or complex. personally, i say the more complex the better.
ok, i'll stop now and wait to see what people think before saying any more.