Nino Bašić: An algorithm for calculating the number of Kekulé structures and Pauling bond orders in benzenoids

Povzetek: An efficient algorithm by John and Sachs for calculating the number of Kekulé structures and Pauling bond orders in benzenoids will be presented.

If time permits, we will also explain the proof of an explicit combinatorial formula for the number of Kekulé structures in hexagonal-shaped benzenoids. A formula for a special case was proposed by Everett (1951) and was slightly generalized by Woodger (1951). Its final form was obtained by Cyvin in 1986. A formal proof was provided 2 years later by Gutman et al.