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 A269359 #7 Mar 14 2016 09:48:03 %S A269359 1,3,2,9,6,5,26,11,4,27,8,65,66,25,16,15,120,71,36,169,76,33,74,41,14, %T A269359 7,10,81,86,185,206,215,22,195,50,19,330,515,196,75,24,337,186,49,46, %U A269359 45,348,247,44,35,358,213,116,353,290,143,106,507,536,295,1266,1345,226,99,12,13,512,2321,220,123,18,1285,306,23,40,21 %N A269359 Self-inverse permutation of natural numbers: a(1)=1, a(A269360(n)) = A250469(1+a(n)), a(A250469(1+n)) = A269360(a(n)). %H A269359 Antti Karttunen, <a href="/A269359/b269359.txt">Table of n, a(n) for n = 1..607</a> %H A269359 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A269359 a(1) = 1, after which for even n, a(n) = A250469(1+a(A268674(n-1))), for odd n, a(n) = A269360(a(A268674(n)-1)). %F A269359 The declarative form can be expressed in terms of A250469 only: %F A269359 a(1)=1, a(1+A250469(n)) = A250469(1+a(n)), a(A250469(1+n)) = 1+A250469(a(n)). %o A269359 (Scheme, with memoization-macro definec) %o A269359 (definec (A269359 n) (cond ((= 1 n) 1) ((even? n) (A250469 (+ 1 (A269359 (A268674 (- n 1)))))) (else (+ 1 (A250469 (A269359 (+ -1 (A268674 n)))))))) %Y A269359 Cf. A250469, A268674, A269360. %Y A269359 Similar or related permutations: A244319, A269863, A269864, A269865, A269866, A269867. %K A269359 nonn %O A269359 1,2 %A A269359 _Antti Karttunen_, Mar 13 2016