# A247033 (b-file synthesized from sequence entry) 1 0 2 3 3 8 4 48 5 121 6 312 7 16104 8 122640 9 7596480 10 61171656 11 4093181688 12 2366564736720 13 19924948267224 14 12169835294351280 15 889585277491970400 16 7633882962663652968 17 565719454445904325272 18 365721616371321130128240 19 239498069351503974657030696 20 2084811062715550992506283600