# A073082 (b-file synthesized from sequence entry) 1 1 2 2 3 9 4 10 5 39 6 348 7 1272 8 10682 9 18275 10 414912 11 5606336 12 8712340 13 20920564 14 47201552 15 140142814 16 240574848 17 5459371212 18 16993264107 19 22955387784 20 23807694876 21 33482496720