Entropy of folding of the triangular lattice
Résumé
The problem of counting the different ways of folding the planar triangular lattice is shown to be equivalent to that of counting the possible 3-colourings of its bonds, a dual version of the 3-colouring problem of the hexagonal lattice solved by Baxter. The folding entropy log q per triangle is thus given by Baxter’s formula $\sqrt{3}\Gamma (1/3)$$^{3/2}$ /2$\pi$ = 1.2087