# A149877 (b-file synthesized from sequence entry) 0 1 1 2 2 5 3 14 4 42 5 140 6 480 7 1694 8 6160 9 22768 10 86119 11 329819 12 1276827 13 5009624 14 19807663 15 79034687 16 317771172 17 1284909978 18 5231953571 19 21409625876 20 88032238475 21 363768052841 22 1508700015910 23 6282877542186 24 26257507524764 25 110071406730840 26 462949380985458 27 1952358638292573 28 8255507414702459