# A095004 (b-file synthesized from sequence entry) 1 1 2 10 3 81 4 640 5 5041 6 39690 7 312481 8 2460160 9 19368801 10 152490250 11 1200553201 12 9451935360 13 74414929681 14 585867502090 15 4612525087041 16 36314333194240 17 285902140466881 18 2250902790540810 19 17721320183859601 20 139519658680336000 21 1098435949258828401 22 8647967935390291210