Number of unrooted quartic trees with n (unlabeled) nodes and possessing a centroid; number of n-carbon alkanes C(n)H(2n +2) with a centroid ignoring stereoisomers.

A010372

Number of unrooted quartic trees with n (unlabeled) nodes and possessing a centroid; number of n-carbon alkanes C(n)H(2n +2) with a centroid ignoring stereoisomers.

Terms

    a(0) =1a(1) =0a(2) =1a(3) =1a(4) =3a(5) =2a(6) =9a(7) =8a(8) =35a(9) =39a(10) =159a(11) =202a(12) =802a(13) =1078a(14) =4347a(15) =6354a(16) =24894a(17) =38157a(18) =148284a(19) =237541a(20) =910726a(21) =1511717a(22) =5731580a(23) =9816092a(24) =36797588a(25) =64658432a(26) =240215803a(27) =431987953a(28) =1590507121a(29) =2917928218

External references