login
Permutation of natural numbers: a(1) = 1, a(A179016(1+n)) = 2*a(n), a(A213713(n)) = 1 + 2*a(n), where A179016 is the infinite trunk of binary beanstalk and A213713 is its complement.
6

%I #7 Mar 07 2016 12:31:05

%S 1,3,2,6,7,5,4,12,13,15,14,11,9,25,10,8,27,31,24,29,23,19,26,51,21,30,

%T 17,55,63,49,28,22,59,47,18,39,53,103,50,43,61,20,35,111,127,16,99,57,

%U 54,45,119,95,62,37,79,107,48,207,101,87,123,41,58,46,71,223,38,255,33,199,52,115,109,102,91,239,191,42,125,75,60

%N Permutation of natural numbers: a(1) = 1, a(A179016(1+n)) = 2*a(n), a(A213713(n)) = 1 + 2*a(n), where A179016 is the infinite trunk of binary beanstalk and A213713 is its complement.

%H Antti Karttunen, <a href="/A269401/b269401.txt">Table of n, a(n) for n = 1..10000</a>

%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>

%F a(1) = 1, for n > 1, if A213719(n) = 1 [when n is in A179016] a(n) = 2*a(A269371(n)-1), otherwise a(n) = 1 + 2*a(n-A269371(n)).

%F As a composition of other permutations:

%F a(n) = A269391(A269398(n)).

%o (Scheme, with memoization-macro definec)

%o (definec (A269401 n) (cond ((<= n 1) n) ((zero? (A213719 n)) (+ 1 (* 2 (A269401 (- n (A269371 n)))))) (else (* 2 (A269401 (+ -1 (A269371 n)))))))

%Y Inverse: A269402.

%Y Cf. A179016, A213713, A213719, A269371.

%Y Related or similar permutations: A269391, A269398.

%K nonn,base

%O 1,2

%A _Antti Karttunen_, Mar 05 2016