# A144272 (b-file synthesized from sequence entry) 0 1 1 1 2 4 3 18 4 129 5 1095 6 11880 7 149940 8 2218545 9 37147005 10 699281100 11 14561835750 12 332913128625 13 8280095098275 14 222659485448400 15 6434896997529000 16 198909798356894625 17 6547761582390653625 18 228681849947367316500 19 8445341134525197152250 20 328822530412023653630625