# A372199 (b-file synthesized from sequence entry) 1 1 2 3 3 22 4 150 5 1370 6 14112 7 169884 8 2301264 9 34903584 10 584575200 11 10728401760 12 214047774720 13 4614042856320 14 106866549054720 15 2646889430976000 16 69814736722483200 17 1953778728154982400 18 57822137143219814400 19 1804373878844546150400 20 59213693468692224000000