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 A306844 Number of anti-transitive rooted trees with n nodes. 40
 1, 1, 2, 3, 7, 14, 36, 83, 212, 532, 1379, 3577, 9444, 25019, 66943 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS A rooted tree is anti-transitive if the subbranches are disjoint from the branches, i.e., no branch of a branch is a branch. LINKS Gus Wiseman, The a(7) = 36 anti-transitive rooted trees. Gus Wiseman, The a(10) = 532 anti-transitive rooted trees. EXAMPLE The a(1) = 1 through a(6) = 14 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((o)))   ((oo(o)))                           ((((o))))  (o((oo)))                                      (oo((o)))                                      ((((oo))))                                      (((o)(o)))                                      (((o(o))))                                      ((o((o))))                                      (o(((o))))                                      (((((o))))) MATHEMATICA rtall[n_]:=Union[Sort/@Join@@(Tuples[rtall/@#]&/@IntegerPartitions[n-1])]; Table[Length[Select[rtall[n], Intersection[Union@@#, #]=={}&]], {n, 10}] CROSSREFS Cf. A276625, A279861, A279861, A290689, A290760, A304360. Cf. A324694, A324695, A324738, A324741, A324743, A324751, A324754, A324756, A324758, A324759, A324764. Sequence in context: A191491 A210345 A006660 * A213906 A123777 A245899 Adjacent sequences:  A306841 A306842 A306843 * A306845 A306846 A306847 KEYWORD nonn,more AUTHOR Gus Wiseman, Mar 13 2019 STATUS approved

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Last modified May 29 20:42 EDT 2020. Contains 334710 sequences. (Running on oeis4.)