1. Originally Posted by danny arrigo
How did you arrive at that answer?
Originally Posted by Plato
The points are distinct and collinear for $a=3:$ $\;\;(3,1),~(1,3),~(2,2)$.
that makes things simpler. we now see that its not -no point- now.............so how do we now prove that there are infinitely many of them?

that makes things simpler. we now see that its not -no point- now.............so how do we now prove that there are infinitely many of them?
oh! i think it will now be true of all $a /geq 3$, right??? sorry for the later. its a greater than equal to three.....for all integral values of a....

There is only one solution: $a=3$.