Here's what we know about the numbers (from here ):
"Each card has its own number of experience needed to gain a level. N cards require 10; HN cards require 40; most R cards require 60*; SR cards require 80. (*Halloween Witch, Blessed Seraz, and Sweet Pony require SR levels.)
As ingredients, Normal cards enhance experience a base level of 9 points; HN enhances 36; R enhances 54, and SR enhances 72. Each evolution doubles its effectiveness: N+ enhances 18, N++ enhance 36, and N+++ enhance 72. The only cards that don't follow this formula are Inferior Gunner (twice as effective) and Han+, Knightly+, Lynn+, Maple+, Rose+, Seraz+, Vera+ who are all half as effective.
For the princess cards, Smiles enhance 36, Touches enhance 72, and Blessings enhance 108."
Also, from here : UR cards take 100 xp per level, and give 90 when used as an enchantment component.
As a table:
|XP per level||XP value||Max Level||Atk gain per level||HP gain per level|