Incendax said:1st: 2/1/1?
3rd: 2/2/1?
5th: 2/2/2?
7th: 3/2/2?
9th: 3/3/2?
11th: 3/3/3?
13th: 4/3/3?
15th: 4/4/3?
17th: 4/4/4?
18th: 5/4/4?
Just a theory, but Wizards probably get to know 2 Daily for every 1 Daily they can cast.
Or several encounter powers could lock each other down, like the cleric Channel Divinity powers. That would likely allow for more spells available but fewer useable per encounter. It would also make certain that you don't use the same encounter powers in each encounter.