# A158608 (b-file synthesized from sequence entry) 0 1 1 4 2 20 3 84 4 404 5 1748 6 8212 7 36180 8 167572 9 746452 10 3427604 11 15370836 12 70212500 13 316145876 14 1439545876 15 6497879892 16 29530613908 17 133496692180 18 605986514708 19 2741933589588 20 12437717824916 21 56308655258324 22 255312140456980