53786626921domain: NAppears in sequencesNumber of perfect matchings in graph P_{2} X P_{6} X P_{n}.at n=6A028450Number of perfect matchings in graph P_{6} x P_{6} x P_{n}.at n=2A049507Number of n X n matrices containing a permutation of 1..n*n moving each element at most to a neighboring position.at n=6A181205