What's the word for having the same distance to neighbours?

Solution 1:

You probably mean equidistant:

• Equally distant.

Equidistant:

• 1560s, from French équidistant (14c.), from Late Latin aequidistantem (nominative aequidistans), from aequi- (see equal (adj.)) + distans (see distant). In reference to a type of map projection, from 1866.

(Etymonline)

Solution 2:

The word you want is equidistant.

At equal distances:
the line joins together all points which are equidistant from the two axes

[ODO]

There isn't a word which means not equidistant, because that's the usual case. Being equidistant is the special case which is unusual. You'd need to say something like "all at different distances".

Solution 3:

It sounds like you want dots which are equidistant.

of equal distance : located at the same distance (a location equidistant from two major cities)

Merriam-Webster

As for an opposite, although not an "official" antonym, "non-equidistant" is probably the most appropriate one. It's definitely used by some people, having 49,400 Google results at the time of searching (some of which appear to be quite prolific research papers)