Number of unlabeled rooted trees with n nodes where the outdegrees (branching factors) of at least one pair of adjacent nodes differ by at least two and the outdegrees of at least one pair of adjacent nodes are equal.
A253244
Number of unlabeled rooted trees with n nodes where the outdegrees (branching factors) of at least one pair of adjacent nodes differ by at least two and the outdegrees of at least one pair of adjacent nodes are equal.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =3a(6) =9a(7) =23a(8) =65a(9) =186a(10) =507a(11) =1380a(12) =3764a(13) =10270a(14) =28001a(15) =76568a(16) =209749a(17) =575900a(18) =1584769a(19) =4371279a(20) =12083764a(21) =33477190a(22) =92939305a(23) =258537475a(24) =720575302a(25) =2012021934a(26) =5627886815a(27) =15768237664a(28) =44249863373a(29) =124365487416
External references
- oeis: A253244