# A035617 (b-file synthesized from sequence entry) 0 1 1 0 2 3 3 3 4 15 5 33 6 105 7 297 8 879 9 2631 10 7833 11 23697 12 71385 13 216765 14 657849 15 2003151 16 6103743 17 18624693 18 56870385 19 173760513 20 531128349 21 1623881889 22 4965695331 23 15185222199 24 46435889601 25 141985777503