Number of asymmetric planted projective plane trees with n+1 nodes; bracelets (reversible necklaces) with n black beads and n-1 white beads.

A006079

Number of asymmetric planted projective plane trees with n+1 nodes; bracelets (reversible necklaces) with n black beads and n-1 white beads.

Terms

    a(0) =1a(1) =1a(2) =0a(3) =1a(4) =4a(5) =16a(6) =56a(7) =197a(8) =680a(9) =2368a(10) =8272a(11) =29162a(12) =103544a(13) =370592a(14) =1335504a(15) =4844205a(16) =17672400a(17) =64810240a(18) =238795040a(19) =883585406a(20) =3281967832a(21) =12232957152a(22) =45740929104a(23) =171529130786a(24) =644950721584

External references