# A204686 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 6 4 18 5 62 6 228 7 869 8 3410 9 13663 10 55689 11 230276 12 963851 13 4076429 14 17394641 15 74798044 16 323797908 17 1409980003 18 6171824159 19 27141256911 20 119854448404 21 531261779875 22 2362873352568 23 10541865261557 24 47165485163426 25 211572830443060 26 951338664998601 27 4287174496933723