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!)
A154452 Signature permutation of a Catalan bijection: The inverse of A154451. 6
0, 1, 3, 2, 7, 8, 6, 4, 5, 17, 18, 20, 21, 22, 16, 19, 14, 10, 9, 15, 11, 12, 13, 45, 46, 48, 49, 50, 54, 55, 57, 58, 59, 61, 62, 63, 64, 44, 47, 53, 56, 60, 42, 51, 38, 26, 27, 37, 25, 23, 24, 43, 52, 39, 29, 28, 40, 30, 31, 32, 41, 33, 34, 35, 36, 129, 130, 132, 133, 134 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
COMMENTS
This automorphism of rooted plane binary trees switches the two descendant trees for every other vertex as it descends along the 111... ray, starting swapping already at the root. Specifically, *A154452 = psi(A154442), where the isomorphism psi is given in A153141 (see further comments there).
LINKS
PROG
(Scheme function, destructive implementation of this automorphism acting on S-expressions:) (define (*A154452! s) (cond ((pair? s) (*A069770! s) (*A154450! (cdr s)))) s)
CROSSREFS
Inverse: A154451. a(n) = A069767(A154454(n)) = A057163(A154456(A057163(n))). Cf. A069770, A154450.
Sequence in context: A154455 A082345 A122327 * A130999 A129611 A154456
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 17 2009
STATUS
approved

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 March 29 02:23 EDT 2024. Contains 371264 sequences. (Running on oeis4.)