cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A243066 Permutation of natural numbers, the even bisection of A241909 incremented by one and halved; equally, a composition of A241909 and A048673: a(n) = A048673(A241909(n)).

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%I A243066 #19 Jun 21 2014 14:16:20
%S A243066 1,2,5,3,14,13,41,4,8,63,122,25,365,313,38,6,1094,18,3281,172,188,
%T A243066 1563,9842,61,23,7813,11,1201,29525,123,88574,7,938,39063,113,39,
%U A243066 265721,195313,4688,666,797162,858,2391485,8404,74,976563,7174454,85,68,88,23438,58825,21523361,28
%N A243066 Permutation of natural numbers, the even bisection of A241909 incremented by one and halved; equally, a composition of A241909 and A048673: a(n) = A048673(A241909(n)).
%C A243066 For n > 1, 2n is found in A241909 from the position (2*a(n))-1. I.e., A241909((2*a(n))-1) = 2n for all n >= 2.
%C A243066 Or in other words, a(n) gives the position in the odd bisection of A241909 where 2n is located at.
%C A243066 Are there any other fixed points than 1, 2, 18 and 72?
%H A243066 Antti Karttunen, <a href="/A243066/b243066.txt">Table of n, a(n) for n = 1..512</a>
%H A243066 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%F A243066 a(1) = 1, a(n) = (A241909(2*n)+1)/2.
%F A243066 As a composition of related permutations:
%F A243066 a(n) = A048673(A241909(n)).
%F A243066 a(n) = A241909(A243062(A241909(n))).
%F A243066 For all n>=1, a(2^n) = A006254(n).
%o A243066 (Scheme, two alternatives)
%o A243066 (define (A243066 n) (if (= n 1) 1 (/ (+ 1 (A241909 (* 2 n))) 2)))
%o A243066 (define (A243066 n) (A048673 (A241909 n)))
%Y A243066 Inverse: A243065.
%Y A243066 Cf. A048673, A241909, A243505-A243506, A244152-A244154, A243061-A243062.
%K A243066 nonn
%O A243066 1,2
%A A243066 _Antti Karttunen_, Jun 01 2014