A short proof of the Deutsch-Sagan congruence for connected non crossing graphs
Combinatorics
2014-04-01 v1
Abstract
We give a short proof, using Lagrange inversion, of a congruence modulo 3 for the number of connected noncrossing graphs on n vertices that was conjectured by Emeric Deutsch and Bruce Sagan. A more complicated proof had been given earlier by S.-P. Eu, S.-C. Liu, and Y.-N. Yeh.
Keywords
Cite
@article{arxiv.1403.7656,
title = {A short proof of the Deutsch-Sagan congruence for connected non crossing graphs},
author = {Ira M. Gessel},
journal= {arXiv preprint arXiv:1403.7656},
year = {2014}
}