A number n is triangular if n == 1 + 2 +…+j for some j.

1. A number n is triangular if n == 1 + 2 +…+j fo…
A number n is vesuvian if it is the sum of two different pairs of squares

A number n is vesuvian if it is the sum of two differen…
1. A number n is triangular if n == 1 + 2 +…+j fo…
A number n is vesuvian if it is the sum of two differen…