Bisection of A005043.

Terms

a(0) =0a(1) =1a(2) =6a(3) =36a(4) =232a(5) =1585a(6) =11298a(7) =83097a(8) =625992a(9) =4805595a(10) =37458330a(11) =295673994a(12) =2358641376a(13) =18985057351a(14) =154000562758