Duplicate of A047767.

Terms

a(0) =0a(1) =0a(2) =1a(3) =2a(4) =2a(5) =7a(6) =12a(7) =29a(8) =55a(9) =143a(10) =271a(11) =728a(12) =1428a(13) =3873a(14) =7752a(15) =21318a(16) =43256a(17) =120175