We explain a technique for discovering the number of simple objects in
Z(C), the center of a fusion category C, as well as the combinatorial data
of the induction and restriction functors at the level of Grothendieck rings.
The only input is the fusion ring K(C) and the dimension function K(C)βC.
The method is not guaranteed to succeed (it may give spurious answers besides
the correct one, or it may simply take too much computer time), but it seems it
often does. We illustrate by showing that there are 22 simple objects in the
center of the extended Haagerup subfactor [arXiv:0909.4099].Comment: 10 page