WOLFRAM|DEMONSTRATIONS PROJECT

Sum of Three Triangular Numbers

​
number to represent
99
99 = 6 + 15 + 78
Triangular numbers are integers of the form
(
2
n
+n)/2
; they are 0, 1, 3, 6, 10, 15, 21, 28, …. As a teenager, in 1796, Gauss proved that every positive integer can be written as the sum of three or fewer triangular numbers.