# A066315 (b-file synthesized from sequence entry) 1 1 2 1 3 3 4 7 5 20 6 51 7 154 8 460 9 1476 10 4860 11 16544 12 57321 13 202059 14 720370 15 2593470 16 9408000 17 34350506 18 126108252 19 465200332 20 1723341185 21 6408356052 22 23911255544 23 89495909408 24 335916703284 25 1264114452975 26 4768464107355