# A168594 (b-file synthesized from sequence entry) 0 1 1 1 2 3 3 6 4 20 5 70 6 302 7 1386 8 6902 9 35862 10 194202 11 1082642 12 6191680 13 36141118 14 214715244 15 1294849186 16 7911159522 17 48888093910 18 305165808290 19 1921992409066 20 12202404037088 21 78031629139246 22 502263432618224 23 3252160882871210