This is a puzzle where the constraint CONSECUTIVE is forced.
A similar concept would be the NON-CONSECUTIVE constraint.
It would be interesting to see one (actually I can try & make one if I had the time) where it can be applied to a whole sudoku grid (where the 9 connects next to a 1 or an 8)
The solution can be reprsented with a SINGLE line . The toridal variant would be AWESOME.