Number of forests of labeled rooted trees with n nodes, containing exactly 2 trees of height one, all others having height zero.

A133386

Number of forests of labeled rooted trees with n nodes, containing exactly 2 trees of height one, all others having height zero.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =12a(5) =120a(6) =750a(7) =3780a(8) =16856a(9) =69552a(10) =272250a(11) =1026300a(12) =3762132a(13) =13498056a(14) =47615750a(15) =165683700a(16) =570024240a(17) =1942538592a(18) =6566094450a(19) =22038141420a(20) =73510278380a(21) =243854707320a(22) =804962754750

External references