# A012543 (b-file synthesized from sequence entry) 0 1 1 0 2 12 3 240 4 15120 5 1355520 6 182229696 7 33914060544 8 8338432876800 9 2621544212398080 10 1025337444571630592 11 488344333262321119232 12 278250960368816815149056 13 186888075247900824522915840