A245152 Number of n-node unlabeled rooted trees with thickening limbs.

1, 1, 2, 3, 5, 7, 12, 17, 28, 42, 69, 105, 176, 275, 460, 740, 1244, 2030, 3440, 5695, 9688, 16243, 27758, 46948, 80610, 137401, 236796, 406258, 702720, 1211954, 2103536, 3644413, 6344632, 11035287, 19265731, 33621510, 58848963, 103003059, 180712466, 317122290

Offset: 1

Author

Alois P. Heinz, Jul 12 2014

Keywords

• nonn

Comments

Also the number of (n+1)-node unlabeled rooted trees with thickening limbs and root outdegree (branching factor) 1.

In a rooted tree with thickening limbs the outdegree of a parent node is smaller than or equal to the outdegree of any of its non-leaf child nodes.

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..150

Crossrefs

Row sums of A245151, also (with offset 2) column k=1 of A245151.

Formula

a(n) = Sum_{k=0..n-1} A245151(n,k).