Summing up some cubes I noticed that 1^{3} + 2^{3} + 3^{3} + 4^{3} = 100, which is 10^{2}. And the pattern held as I added more cubes (i.e., I kept getting squares). This is well known in the world of mathematics and number theory, but it was new to me. Extending the pattern:

And that makes these triangular numbers. And that means that every triangular number squared is the sum of cubes. It works both way in being interesting.