# A334580 (b-file synthesized from sequence entry) 1 1 2 4 3 36 4 144 5 3600 6 1200 7 58800 8 235200 9 6350400 10 6350400 11 768398400 12 768398400 13 129859329600 14 129859329600 15 129859329600 16 519437318400 17 150117385017600 18 50039128339200 19 18064125330451200 20 3612825066090240 21 3612825066090240 22 3612825066090240 23 1911184459961736960