On a constructive approach to the calculation of cardinality of the Ryser classes
Владислав С Кроткин, O. V. Kuzmin · Discrete Mathematics and Applications · 2009
We consider the problem of calculation of cardinality of the classes of square matrices consisting of zeros and ones with given values of row and column sums. We obtain a recurrence relation which gives a possibility to calculate the cardinalities of these classes. In the proofs, we use a constructive approach, that is, we construct the combinatorial objects with given characteristics and calculate the number of distinct objects. An example of the use of the obtained relation is given.