A281578 Maximum number of nonisomorphic root-containing subtrees of a rooted tree of order n

1, 2, 3, 5, 7, 11, 16, 24, 34, 54, 79, 119, 169, 269, 394, 594, 850

Offset

1,2

Comments

Isomorphism is understood in the rooted sense: isomorphisms have to preserve the root.

Links

Table of n, a(n) for n=1..17.

Éva Czabarka, László A. Székely and Stephan Wagner, On the number of nonisomorphic subtrees of a tree, arXiv:1601.00944 [math.CO], 2016.

Manfred Scheucher, Sage Script (dynamic programming)

Example

For n=4, the unique rooted tree with two branches of order 1 and 2 respectively has a(4)=5 nonisomorphic subtrees containing the root: one each of order 1,2,4, and two of order 3. The three other rooted trees of order 4 have only four nonisomorphic subtrees.

Crossrefs

Cf. A281094.

Sequence in context: A326467 A326592 A226541 * A173199 A023435 A274184

Adjacent sequences: A281575 A281576 A281577 * A281579 A281580 A281581

Keyword

nonn,more

Author

Stephan Wagner, Jan 24 2017

Extensions

a(16)-a(17) from Manfred Scheucher, Mar 11 2018

Status

approved