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 A048816 Number of rooted trees with n nodes with every leaf at the same height. 38
 1, 1, 2, 3, 5, 7, 12, 17, 28, 42, 68, 103, 168, 260, 420, 665, 1075, 1716, 2787, 4489, 7304, 11849, 19333, 31504, 51561, 84347, 138378, 227096, 373445, 614441, 1012583, 1669774, 2756951, 4555183, 7533988, 12469301, 20655523, 34238310, 56795325, 94270949 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS The trees are unordered (see A000081). For balanced ordered rooted trees see A079500. - Joerg Arndt, Jul 20 2014 The trees are unlabeled. For labeled version see A238372. - Alois P. Heinz, Dec 29 2014 LINKS Vaclav Kotesovec, Table of n, a(n) for n = 1..3500 (terms 1..300 from Alois P. Heinz) Joerg Arndt, balanced unordered rooted trees for n = 1..10 EXAMPLE See Arndt link. From Gus Wiseman, Oct 08 2018: (Start) The a(1) = 1 through a(7) = 12 balanced rooted trees with n nodes:   o  (o)  (oo)   (ooo)    (oooo)     (ooooo)      (oooooo)           ((o))  ((oo))   ((ooo))    ((oooo))     ((ooooo))                  (((o)))  (((oo)))   (((ooo)))    (((oooo)))                           ((o)(o))   ((o)(oo))    ((o)(ooo))                           ((((o))))  ((((oo))))   ((oo)(oo))                                      (((o)(o)))   ((((ooo))))                                      (((((o)))))  (((o)(oo)))                                                   ((o)(o)(o))                                                   (((((oo)))))                                                   ((((o)(o))))                                                   (((o))((o)))                                                   ((((((o)))))) (End) MATHEMATICA T[n_, k_] := T[n, k] = If[n==1, 1, If[k==0, 0, Sum[Sum[If[d

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Last modified May 24 16:21 EDT 2020. Contains 334574 sequences. (Running on oeis4.)