Let Dn be the set of all signed permutations on n = {1,...,n} with even signs,and let Dn(T) be the set of all signed permutations in Dn which avoids a set T of signed patterns.In this paper,we find all the cardinaliti...Let Dn be the set of all signed permutations on n = {1,...,n} with even signs,and let Dn(T) be the set of all signed permutations in Dn which avoids a set T of signed patterns.In this paper,we find all the cardinalities of the sets Dn(T) where T■B2.Some of the cardinalities encountered involve inverse binomial coefficients,binomial coefficients,Catalan numbers,and Fibonacci numbers.展开更多
基金The National Natural Science Foundation of China （No. 10801020）.
文摘Let Dn be the set of all signed permutations on n = {1,...,n} with even signs,and let Dn(T) be the set of all signed permutations in Dn which avoids a set T of signed patterns.In this paper,we find all the cardinalities of the sets Dn(T) where T■B2.Some of the cardinalities encountered involve inverse binomial coefficients,binomial coefficients,Catalan numbers,and Fibonacci numbers.
