[1] **viXra:1103.0031 [pdf]**
*submitted on 10 Mar 2011*

**Authors:** Marco Ripà

**Comments:** 3 pages

In this paper we provide an inverse proof of the relation between a particular class of double sums
and tetrahedral numbers. Thus, we present a compact formula to reduce the number of calculations
necessary to solve such a kind of problems. The initial identity is confirmed "a posteriori" using
the formula mentioned above.

**Category:** Algebra