login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A072094 Permutation of natural numbers induced by the automorphism cdr_robr_cdr! acting on the parenthesizations encoded by A014486. 4
0, 1, 3, 2, 7, 8, 5, 4, 6, 17, 18, 20, 21, 22, 13, 12, 10, 9, 11, 15, 14, 16, 19, 45, 46, 48, 49, 50, 54, 55, 57, 58, 59, 61, 62, 63, 64, 35, 36, 32, 31, 34, 26, 27, 24, 23, 25, 29, 28, 30, 33, 41, 40, 38, 37, 39, 43, 42, 44, 47, 52, 51, 53, 56, 60, 129, 130, 132, 133, 134 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..69.

A. Karttunen, Gatomorphisms (Includes the complete Scheme program for computing this sequence)

Index entries for sequences that are permutations of the natural numbers

PROG

(Scheme function implementing this automorphism on list-structures:)

(define (cdr_robr_cdr! s) (cond ((not (pair? s))) ((not (pair? (car s))) (swap! s)) (else (cdr_robr_cdr! (cdr s)) (robr! s) (cdr_robr_cdr! (cdr s)))) s)

(define (robr! s) (let ((ex-cdr (cdr s))) (set-cdr! s (caar s)) (set-car! (car s) ex-cdr) (swap! (car s)) (swap! s) s))

(define (swap! s) (let ((ex-car (car s))) (set-car! s (cdr s)) (set-cdr! s ex-car) s))

CROSSREFS

Inverse permutation: A072095. The car/cdr-flipped conjugate of A072093, i.e. A072094(n) = A057163(A072093(A057163(n))). Cf. also A071655-A071660, A072090-A072091.

Sequence in context: A130964 A130929 A073270 * A122330 A082322 A130953

Adjacent sequences:  A072091 A072092 A072093 * A072095 A072096 A072097

KEYWORD

nonn

AUTHOR

Antti Karttunen, Jun 25 2002

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy .

Last modified December 6 12:54 EST 2016. Contains 278781 sequences.