|
| |
|
|
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, 37553, 101992, 276995, 752307, 2043218, 5549310, 15071694, 40934215, 111175866, 301949926, 820085698, 2227325273, 6049340413, 16429805791, 44622800991, 121194031561, 329158925122, 893984605415, 2428032213452
(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
|
|
|
|
CROSSREFS
|
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
|
|
|
EXTENSIONS
|
|
|
|
STATUS
|
approved
|
| |
|
|
