OFFSET
1,2
COMMENTS
If f(n) denotes the binary tree representation of n defined in A324556, then this sequence lists the n such that f(n) is symmetrical.
LINKS
Luc Rousseau, Table of n, a(n) for n = 1..200
Luc Rousseau, A program to compute this sequence (SWI-Prolog).
EXAMPLE
34 is '100010' in binary, which is a one, followed by 3 zeros, followed by '10' = 2. Then, following the rules specified in A324556, 34 can be represented by the partial decomposition tree:
34
/ \
2 3
Pursuing the decomposition process yields the complete decomposition tree:
34
/ \
/ \
/ \
/ \
/ \
2 3
/ \ / \
0 1 1 0
/ \ / \
0 0 0 0
With values removed, this tree is symmetrical. So, 34 is in the sequence.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Luc Rousseau, Mar 15 2019
STATUS
approved