login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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

%I #6 Feb 15 2022 20:55:22

%S 1,2,5,13,35,94,255,691,1876,5092,13829,37553,101992,276995,752307,

%T 2043218,5549310,15071694,40934215,111175866,301949926,820085698,

%U 2227325273,6049340413,16429805791,44622800991,121194031561,329158925122,893984605415,2428032213452

%N 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.

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

%H Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a054/A054657.java">Java program</a> (github)

%K nonn

%O 1,2

%A _John W. Layman_, Apr 17 2000

%E More terms from _Sean A. Irvine_, Feb 15 2022

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 23 02:53 EDT 2024. Contains 371906 sequences. (Running on oeis4.)