# A370284 (b-file synthesized from sequence entry) 0 1 1 3 2 21 3 168 4 1425 5 12483 6 111594 7 1011636 8 9264753 9 85510590 10 794087151 11 7410887718 12 69446624910 13 653019755430 14 6158495001960 15 58226492157048 16 551725482707505 17 5238008159399163 18 49814314319342424 19 474467729545936650 20 4525387365179378775