Uniqueness of pair $\left(a,b\right)$ in writing positive integer $V$ as $V=a^2+ab+b^2$ with $a, b \in \mathbb{N}$
It's not unique. $$(a,b)=(6,5)\implies a^2+ab+b^2=36+30+25=91$$
$$(a,b)=(9,1)\implies a^2+ab+b^2=81+9+1=91$$
It's not unique. $$(a,b)=(6,5)\implies a^2+ab+b^2=36+30+25=91$$
$$(a,b)=(9,1)\implies a^2+ab+b^2=81+9+1=91$$