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A054657 Number of leaves on the rooted tree of height n constructed by the following rule. Assign weight 1 to the single node at height 1. At each node of weight w at height k>0, branch to nodes at height k+1 as follows: one node of weight 1 and a node of weight d+1 if d divides w. 1
1, 2, 5, 13, 35, 94, 255, 691, 1876, 5092, 13829 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

If the condition "d divides w" in the definition is replaced by "d<=w" then sequence A000108 (the Catalan numbers) is obtained.

LINKS

Table of n, a(n) for n=1..11.

CROSSREFS

Sequence in context: A097919 A160438 A240609 * A024576 A057960 A227045

Adjacent sequences:  A054654 A054655 A054656 * A054658 A054659 A054660

KEYWORD

nonn

AUTHOR

John W. Layman, Apr 17 2000

STATUS

approved

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Last modified May 26 02:35 EDT 2019. Contains 323579 sequences. (Running on oeis4.)