# A006815 (b-file synthesized from sequence entry) 1 1 2 6 3 23 4 84 5 283 6 930 7 2921 8 9096 9 27507 10 82930 11 244819 12 722116 13 2096603 14 6087290 15 17458887 16 50090544 17 142317089 18 404543142