Square Lattice Self-Avoiding Walks and Polygons

We give an algorithm for the enumeration of self-avoiding walks on the (anisotropic) square lattice. Application of the algorithm on a 1024 processor Intel Paragon supercomputer resulted in a 51 term series. For (isotropic) square lattice self-avoiding polygons, a related algorithm has produced a 90 term series. Careful analysis provides compelling evidence for simple rational values of the exponents in both the dominant and subdominant terms in the asymptotic form of the coefficients. We also advance compelling arguments – but not a proof – that the generating function for SAW is not differentiably finite. The corresponding result for SAP has recently been proved.