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 A324765 Number of recursively anti-transitive rooted trees with n nodes. 14
 1, 1, 2, 3, 6, 11, 26, 52, 119, 266, 618, 1432, 3402, 8093, 19505, 47228, 115244, 282529, 696388, 1723400 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS An unlabeled rooted tree is recursively anti-transitive if no branch of a branch of a terminal subtree is a branch of the same subtree. LINKS EXAMPLE The a(1) = 1 through a(6) = 11 recursively anti-transitive rooted trees:   o  (o)  (oo)   (ooo)    (oooo)     (ooooo)           ((o))  ((oo))   ((ooo))    ((oooo))                  (((o)))  (((oo)))   (((ooo)))                           ((o)(o))   ((o)(oo))                           (o((o)))   (o((oo)))                           ((((o))))  (oo((o)))                                      ((((oo))))                                      (((o)(o)))                                      ((o((o))))                                      (o(((o))))                                      (((((o))))) MATHEMATICA nallt[n_]:=Select[Union[Sort/@Join@@(Tuples[nallt/@#]&/@IntegerPartitions[n-1])], Intersection[Union@@#, #]=={}&]; Table[Length[nallt[n]], {n, 10}] CROSSREFS Cf. A000081, A290689, A301700, A304360, A306844, A317787, A318185. Cf. A324695, A324751, A324756, A324758, A324764, A324766, A324767, A324768. Cf. A324838, A324840, A324844. Sequence in context: A107113 A156807 A032256 * A208602 A051603 A094927 Adjacent sequences:  A324762 A324763 A324764 * A324766 A324767 A324768 KEYWORD nonn,more AUTHOR Gus Wiseman, Mar 17 2019 STATUS approved

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Last modified March 29 02:19 EDT 2020. Contains 333104 sequences. (Running on oeis4.)