OFFSET
1,2
COMMENTS
We have binary trees with the desired properties for every height n > 0:
- for n = 1: we have the following tree B_1:
1^2
|
- for any n > 0, provided we have B_n, we can build a tree B_{n+1) as follows:
3^2*B_n 4^2*B_n
\ /
\ /
\ /
(5^n)^2
|
- hence the sequence is well defined.
LINKS
Rémy Sigrist, Illustration of first terms
Rémy Sigrist, C++ program for A309167
EXAMPLE
a(1) = 1:
1^2
|
a(2) = 5:
3^2 4^2
\ /
\ /
5^2
|
a(3) = 13:
3^2 4^2
\ /
\ /
5^2 12^2
\ /
\ /
13^2
|
PROG
(C++) See Links section.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Rémy Sigrist, Jul 15 2019
EXTENSIONS
a(29)-a(32) from Rémy Sigrist, Nov 16 2020
STATUS
approved