# A180897 (b-file synthesized from sequence entry) 1 1 2 0 3 2 4 6 5 30 6 180 7 1260 8 10080 9 90720 10 907200 11 9797760 12 114287040 13 1416703680 14 18712086480 15 260499022680 16 3833521421760 17 59158317014280 18 959784091498944