posts on each page in a thread

[Trilogy]

every page has 20 posts, so you would have to multiply 20 by 2 for every page number. You dont need to complete a page by overpassing the number, this is just the same (20 posts, new page)

20= Page 1
40= Page 2
60= Page 3
80= Page 4
100= Page 5
and so on...