# A038054 (b-file synthesized from sequence entry) 0 1 1 2 2 4 3 12 4 80 5 800 6 10752 7 181888 8 3714048 9 88915968 10 2442936320 11 75776712704 12 2619618852864 13 99879826948096 14 4163954627051520 15 188441538173337600 16 9200521811924615168 17 482067547423055544320 18 26980938272912248406016