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 A071655 Permutation of natural numbers induced by the automorphism robr_car_cdr! acting on the parenthesizations encoded by A014486. 15
 0, 1, 3, 2, 7, 8, 5, 4, 6, 17, 18, 20, 21, 22, 12, 13, 10, 9, 11, 15, 14, 19, 16, 45, 46, 48, 49, 50, 54, 55, 57, 58, 59, 61, 62, 63, 64, 31, 32, 34, 35, 36, 26, 27, 24, 23, 25, 29, 28, 33, 30, 40, 41, 38, 37, 39, 52, 51, 56, 60, 43, 42, 47, 44, 53, 129, 130, 132, 133, 134 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS A. Karttunen, Gatomorphisms (Includes the complete Scheme source for computing this sequence) PROG (Scheme function implementing this automorphism on list-structures:) (define (robr_car_cdr! s) (cond ((not (pair? s))) ((not (pair? (car s))) (swap! s)) (else (robr! s) (robr_car_cdr! (car s)) (robr_car_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: A071656. The car/cdr-flipped conjugate of A071660, i.e. A071655(n) = A057163(A071660(A057163(n))). Cf. also A071657, A071658. Sequence in context: A129610 A130923 A057501 * A130964 A130929 A073270 Adjacent sequences:  A071652 A071653 A071654 * A071656 A071657 A071658 KEYWORD nonn AUTHOR Antti Karttunen, May 30 2002 STATUS approved

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Last modified December 11 23:44 EST 2019. Contains 329945 sequences. (Running on oeis4.)