You can "change sides" by adding number of sides (say, from a triangle to a square) or by adding side length (say, from area 4 to 9).
The 1 in each line represents the first letter of that line's word, because one dot can represent the smallest n-gon for any n.
Each page also corresponds to one word.
35 is the fifth pentagonal number, while 36 is the third tridecagonal number, and 246 is the sixth octadecagonal number. (Did we mention NUMBERs?)
A general formula might help you explain the negative numbers (and save a bunch of time).