User blog comment:Jimeee/Skyrim 1.9 beta update adds Legendary difficulty and raises level cap (Updated Apr 8th)/@comment-206.248.75.2-20130326200635

Each skill tree has 6 skills. The oghma infinitum increases 5 levels to each skill. Since the skills reset to lb 15, u would need 13 books to complete a hole skill tree. Multiply it by 3 for there r 3 skill trees. That makes for 39 books. U need a 169 levels to get from level 81 to level 250. Each oghma infinitum increases around 1 level. Making it for a total of 169 oghma infiniums. if u divide 169 with 39 witch r the sets of books per prestige, that gives a total of 4.3. Meaning ull have 2 reset ur skills around 4 times. Since the level increase is not allways accurate, I sudjest that 175 oghma infiniums r required to reach lv. 250.