The basis functions for our G2 biseptic spline, for valence 3 through 12, can be found here:
Similar basis functions, that interpolate the Catmull-Clark limit surface, can be found here:
A simple C++ program that reads and prints the basis functions can be found here:
The ordering of the basis functions within the files follows this diagram:
Note that this is same ordering used in Jos Stam's exact evaluation paper