# A149943 (b-file synthesized from sequence entry) 0 1 1 2 2 5 3 15 4 49 5 172 6 627 7 2374 8 9218 9 36536 10 147576 11 604114 12 2505636 13 10503384 14 44429132 15 189530129 16 814217984 17 3520596956 18 15311050911 19 66930619301 20 293971727765 21 1296689732244 22 5742062449808 23 25518877148421 24 113785729926120 25 508913759962817 26 2282592025746653 27 10264924766267955