Lattice path enumeration for semi-magic squares of size three
arXiv:2107.09463
Abstract
We give formulas for enumerating directed paths in the graded poset of semi-magic squares of size three. We give two applications of these formulas: an advanced example of Vandermonde convolution for finite graded posets, and a direct method for deriving Regge symmetry formulas for un-normalized Clebsch-Gordan coefficients.
15 pages, updated references and added 2 figures, no material changes but many minor improvements