Abstract: 
I discuss recent work on efficiently computing the basic functions of
Lorenztian spin foam models, from which the amplitudes themselves are
calculated. The focus is on computing the 6J and 10J symbols, and I
show how starting from the expression for these functions as integrals
over copies of the group SL(2,C), one can develop an efficient
algorithm for the 6J symbol, which can then be applied in calculating
the 10J symbol.
