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.
%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