# A064647 (b-file synthesized from sequence entry) 1 2 2 3 3 10 4 105 5 770 6 15015 7 170170 8 4849845 9 6760390 10 3234846615 11 200560490130 12 72752334655 13 4680773285034 14 284407855036305 15 614889782588491410 16 465559406817000639 17 44715356980330526490 18 19548063559901161830545