# A173499 (b-file synthesized from sequence entry) 1 0 2 0 3 2 4 20 5 204 6 2604 7 39990 8 720600 9 14913080 10 348678440 11 9090909090 12 261535698060 13 8230246567620 14 281241170407092 15 10371206370520814 16 410525522232055664 17 17361641481138401520 18 781282469559318055056