btiemann
The six-ball siteswap 999441. Note that there are 3, 2, and 1 throws of each different height, which have heights of 3^2, 2^2, and 1^1. The sum of the throws are then 3^3 + 2^3 + 1^1, which is the square of the third triangular number (1+2+3)^2. How about that? This works in general, by the way.