Use your math skills and hop to that page number.
Take this topic for example:
viewtopic.php?f=30&t=49&st=0&sk=t&sd=a&start=1965If you go to the same URL, but change the number at the end to a multiple of 15, you get that number+=page number
15*44=660
viewtopic.php?f=30&t=49&st=0&sk=t&sd=a&start=660Goes to page 44+1. Page 45
Hop to page number would be a bit more convenient, but it's not like you CAN'T get to a page you need to.