## The 166-th triangular number

An integer of the form   $T_{n} \; = \; n \, (n + 1)/2$   is called a Triangular number.

The 166-th triangular number is :      $T_{166} \; = \; 13861$

$22^3 + 14^3 + 7^3 + 5^3 + 1^3 \; = \; 18^3 + 18^3 + 13^3 \; = \; 13861$

and

$22 + 14 + 7 + 5 + 1 \; = \; 18 + 18 + 13 \; = \; 7^2$