# A150015 (b-file synthesized from sequence entry) 0 1 1 2 2 5 3 18 4 66 5 240 6 960 7 3868 8 15717 9 66099 10 278019 11 1184631 12 5122091 13 22145476 14 96822325 15 426006332 16 1877617552 17 8342165233 18 37163619077 19 166066819583 20 745941334923 21 3355458551285 22 15145356845178 23 68575254267863 24 310903375989401 25 1413892090253073 26 6441832176113612 27 29393857347481750