We introduce a generic approach for counting subgraphs in a graph. The main idea is to relate counting subgraphs to counting graph homomorphisms. This approach provides new algori...
1 Rational functions and minimal factorizations of permutations Let f : C C be a rational function of degree n in one complex variable. A critical point of f is a point z C such...
We define incidence matrices to be zero-one matrices with no zero rows or columns. We are interested in counting incidence matrices with a given number of ones, irrespective of th...
Recently, Kitaev and Remmel [8] refined the well-known permutation statistic "descent" by fixing parity of one of the descent's numbers. Results in [8] were extende...