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!)
A243346 a(1) = 1, a(2n) = A005117(1+a(n)), a(2n+1) = A013929(a(n)), where A005117 are squarefree and A013929 are nonsquarefree numbers. 13

%I #11 Jun 08 2014 08:58:57

%S 1,2,4,3,8,6,12,5,9,13,24,10,18,19,32,7,16,14,25,21,36,38,63,15,27,30,

%T 49,31,50,53,84,11,20,26,45,22,40,39,64,34,54,59,96,62,99,103,162,23,

%U 44,42,72,47,80,79,126,51,81,82,128,86,136,138,220,17,28,33,52,41,68,73,120

%N a(1) = 1, a(2n) = A005117(1+a(n)), a(2n+1) = A013929(a(n)), where A005117 are squarefree and A013929 are nonsquarefree numbers.

%C This permutation entangles complementary pair A005843/A005408 (even/odd numbers) with complementary pair A005117/A013929 (numbers which are squarefree/are not squarefree).

%H Antti Karttunen, <a href="/A243346/b243346.txt">Table of n, a(n) for n = 1..8189</a>

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

%F a(1) = 1, a(2n) = A005117(1+a(n)), a(2n+1) = A013929(a(n)).

%F For all n > 1, A008966(a(n)) = A000035(n+1), or equally, mu(a(n)) + 1 = n modulo 2, where mu is Moebius mu (A008683). [A property shared with a simpler variant A075378].

%o (Scheme, with memoizing macro definec from _Antti Karttunen_'s IntSeq-library)

%o (definec (A243346 n) (cond ((<= n 1) n) ((even? n) (A005117 (+ 1 (A243346 (/ n 2))))) (else (A013929 (A243346 (/ (- n 1) 2))))))

%Y Inverse: A243345.

%Y Cf. A005843, A005408, A008966, A005117, A013929, A013928, A057627.

%Y Similar permutations: A075378, A243343-A243344, A243347, A243287-A243288, A135141-A227413, A237126-A237427, A193231.

%K nonn

%O 1,2

%A _Antti Karttunen_, Jun 03 2014

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 April 18 10:01 EDT 2024. Contains 371779 sequences. (Running on oeis4.)