points in a grid

hello
I created a plane from which I created a grid of points. I want to join these points with a plolilinea to form a sort of square spiral.
I've noticed that if you select the first point of the first list, along with the first point ofthe last list, and the last point of the last list and the last point of the first list and then the second point of the first list , then the second point on the penultimate list, andLuengo the penultimate point of the penultimate achievement susecivamente list andso the spiral form but not how to do this ....

any help is appreciated

x 0 0 0 0 x

x 1 1 1 x 1

2 x 2 x 2 2

3 x 3 3 x 3

x 4 4 4 4 x