# A003609 (b-file synthesized from sequence entry) 1 1 2 2 3 2 4 10 5 14 6 42 7 90 8 354 9 758 10 2290 11 6002 12 18410 13 51310 14 154106 15 449322 16 1384962 17 4089174 18 12475362 19 37746786 20 116037642 21 355367310 22 1097869386 23 3393063162 24 10546081122 25 32810171382 26 102465452754 27 320522209490 28 1005428474218