Number of rooted trees with n nodes such that no more than two subtrees corresponding to children of any node have the same number of nodes.

A213920

Number of rooted trees with n nodes such that no more than two subtrees corresponding to children of any node have the same number of nodes.

Terms

    a(0) =0a(1) =1a(2) =1a(3) =2a(4) =3a(5) =7a(6) =15a(7) =34a(8) =79a(9) =190a(10) =457a(11) =1132a(12) =2823a(13) =7126a(14) =18136a(15) =46541a(16) =120103a(17) =312109a(18) =815012a(19) =2137755a(20) =5632399a(21) =14895684a(22) =39519502a(23) =105198371a(24) =280815067a(25) =751490363a(26) =2016142768a(27) =5420945437a(28) =14604580683a(29) =39425557103

External references