# A371233 (b-file synthesized from sequence entry) 0 1 1 0 2 0 3 6 4 12 5 40 6 1620 7 16128 8 154560 9 3378240 10 67828320 11 1247843520 12 28996704000 13 773215822080 14 20900234234880 15 609432997219200 16 19677823129036800 17 674330219708221440 18 24327437969162280960 19 936555233579552563200 20 38250260222888409292800