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 A218602 #14 Mar 08 2025 14:54:45 %S A218602 0,1,2,4,3,7,6,5,12,11,10,9,8,21,20,19,18,17,16,15,14,13,38,37,36,35, %T A218602 34,33,32,31,30,29,28,27,26,25,24,23,22,68,67,66,65,64,63,62,61,60,59, %U A218602 58,57,56,55,54,53,52,51,50,49,48,47,46,45,44,43,42,41,40,39 %N A218602 Simple self-inverse permutation of natural numbers: after zero, list each block of A213709(n) numbers in reverse order, from A218600(n) to A213710(n-1). %C A218602 This permutation can be used to map between the sequences A179016 and A218616. E.g. A179016(n) = A218616(a(n)) and vice versa: A218616(n) = A179016(a(n)). %H A218602 Antti Karttunen, <a href="/A218602/b218602.txt">Table of n, a(n) for n = 0..8727</a> %H A218602 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A218602 a(n) = A218600(A213711(n))-A218601(n). %o A218602 (Scheme) (define (A218602 n) (- (A218600 (A213711 n)) (A218601 n))) %Y A218602 Cf. A179016, A218616, A054429, A130918, A054430. %K A218602 nonn %O A218602 0,3 %A A218602 _Antti Karttunen_, Nov 10 2012