# A073975 (b-file synthesized from sequence entry) 1 0 2 0 3 0 4 12 5 180 6 1440 7 9072 8 54432 9 308448 10 1700352 11 9722592 12 58335552 13 356638464 14 2173796352 15 13144674816 16 78940272384 17 472093588224 18 2821539889152 19 16894457846784 20 101366747080704 21 608795590588416 22 3656220357427200 23 21947538146863104 24 131685228881178624