A057508 - OEIS

A057508

Self-inverse permutation of natural numbers induced by the function 'reverse' (present in programming languages like Lisp, Scheme, Prolog and Haskell) when it acts on symbolless S-expressions encoded by A014486/A063171.

0, 1, 2, 3, 4, 6, 5, 7, 8, 9, 14, 11, 16, 19, 10, 15, 12, 17, 18, 13, 20, 21, 22, 23, 37, 28, 42, 51, 25, 39, 30, 44, 47, 33, 53, 56, 60, 24, 38, 29, 43, 52, 26, 40, 31, 45, 46, 32, 48, 49, 50, 27, 41, 34, 54, 55, 35, 57, 58, 59, 36, 61, 62, 63, 64, 65, 107, 79, 121, 149, 70

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OFFSET

0,3

LINKS

Table of n, a(n) for n=0..70.

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

Index entries for the sequences induced by list functions of Lisp

Index entries for signature-permutations induced by Catalan automorphisms

MAPLE

Similar function for Maple lists can be implemented as: reverse := proc(a) if 0 = nops(a) then (a) else [op(reverse(cdr(a))), a[1]]; fi; end;

PROG

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

(Destructive variant, see A057509 for Rol!) (define (Rev1! s) (cond ((pair? s) (Rev1! (cdr s)) (Rol! s))) s)

(Another variant, see A057510 for Ror!) (define (Rev2! s) (cond ((pair? s) (Ror! s) (Rev2! (cdr s)))) s)

CROSSREFS

The car/cdr-flipped conjugate of A069769, i.e. A057508(n) = A057163(A069769(A057163(n))). Cf. also A057164, A057509, A057510, A033538.

Sequence in context: A130945 A073285 A057512 * A057164 A085175 A130111

Adjacent sequences: A057505 A057506 A057507 * A057509 A057510 A057511

KEYWORD

nonn

AUTHOR

Antti Karttunen Sep 03 2000

STATUS

approved