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Number of trees with n unlabeled nodes such that all nodes of degree >2 lie on a single path.
0

%I #13 Dec 11 2016 06:55:33

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

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

%C First differs from A000055 at a(10).

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

%e a(10) = 105 counts all trees except for the following.

%e o o

%e \ /

%e o

%e |

%e o

%e / \

%e o o

%e / \ / \

%e o o o o

%Y Cf. A000055, A130131, A277795.

%K nonn,more

%O 0,5

%A _Gabriel Burns_, Oct 31 2016