# A150070 (b-file synthesized from sequence entry) 0 1 1 2 2 6 3 18 4 64 5 220 6 782 7 2824 8 10328 9 38306 10 142388 11 533832 12 2011048 13 7609034 14 28938148 15 110276428 16 421716538 17 1616589438 18 6211475088 19 23925481704 20 92285891638 21 356644978016 22 1380284689858 23 5349558200316 24 20763135142878 25 80668088650424 26 313779804455788 27 1221721443853960 28 4761378554236090