A277796 Number of trees with n unlabeled nodes such that all nodes of degree >2 lie on a single path.

1, 1, 1, 1, 2, 3, 6, 11, 23, 47, 105, 231, 537

Offset

0,5

Comments

First differs from A000055 at a(10).

First differs from A130131 at a(12), n >= 1.

Links

Table of n, a(n) for n=0..12.

Example

a(10) = 105 counts all trees except for the following.
     o   o
      \ /
       o
       |
       o
     /   \
    o     o
   / \   / \
  o   o o   o

Crossrefs

Cf. A000055, A130131, A277795.

Sequence in context: A303586 A130131 A338355 * A123465 A000055 A217312

Adjacent sequences: A277793 A277794 A277795 * A277797 A277798 A277799

Keyword

nonn,more

Author

Gabriel Burns, Oct 31 2016

Status

approved