# Algebra

posted by
**Stranger**
.

How many positive integers n≤1000 cannot be written in the form a2−b2−c2 where a,b and c are non-negative integers subject to a≥b+c?

posted by
**Stranger**
.

How many positive integers n≤1000 cannot be written in the form a2−b2−c2 where a,b and c are non-negative integers subject to a≥b+c?