Number of tiered orders on n nodes (corrected version of A006860).

A223911

Number of tiered orders on n nodes (corrected version of A006860).

Terms

    a(0) =1a(1) =1a(2) =3a(3) =13a(4) =111a(5) =1381a(6) =25623a(7) =678133a(8) =26169951a(9) =1447456261a(10) =114973232583

External references