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 A277795 Number of trees with n unlabeled nodes such that all nodes with degree >2 lie on a single path with length equal to the tree's diameter. 2
 1, 1, 1, 1, 2, 3, 6, 11, 23, 47, 103, 223, 503, 1132, 2602, 5986, 13922, 32433, 75994, 178354, 419945, 990134, 2339033, 5531459 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 COMMENTS First differs from A000055 at a(10). First differs from A130131 at a(10), n >= 1. The ratio of consecutive terms seems to tend to some limit. - Andrey Zabolotskiy, Dec 12 2016 LINKS Andrey Zabolotskiy, Python script for the sequence EXAMPLE From Andrey Zabolotskiy, Nov 21 2016: (Start) Three trees that are counted in A000055(10) but not in a(10): (1) o o-o-o | | o----o | | o o-o-o (2) o-o-o | o-o-o-o | o-o-o (3) o-o-o-o-o-o-o | o-o-o (End) CROSSREFS Cf. A000055, A130131. Sequence in context: A359392 A199142 A090344 * A198662 A198620 A198648 Adjacent sequences: A277792 A277793 A277794 * A277796 A277797 A277798 KEYWORD nonn,more AUTHOR Gabriel Burns, Oct 31 2016 EXTENSIONS Corrections and more terms from Andrey Zabolotskiy, Nov 21 2016 STATUS approved

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Last modified March 24 06:31 EDT 2023. Contains 361454 sequences. (Running on oeis4.)