# A145620 (b-file synthesized from sequence entry) 1 1 2 2 3 5 4 140 5 35 6 770 7 5005 8 40040 9 510510 10 646646 11 323323 12 29745716 13 14300825 14 12257850 15 59246275 16 29386152400 17 7346538100 18 77138650050 19 475688341975 20 24735793782700 21 253541886272675 22 21804602219450050 23 10902301109725025