(refer to my second article from the second MHFzine)

With this trigrade (2,8,9,15)^3 = (3,5,12,15)^3;
the results are 34, 374 and 4624 for levels 1 - 3 and 374/34 = 11 and 4624/34 = 136.

I've checked other multigrades whereby you can't evenly divide a higher level by a lower level and when you can, there doesn't seem to be a pattern to the results. Is anyone aware whether this area of math has been researched and studied (and can easily be accessed from the internet)?