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 A108971 #13 Jun 20 2018 01:36:20 %S A108971 1,2,3,4,5,6,7,8,9,17,16,15,14,13,12,11,10,20,21,22,23,24,25,26,18,19, %T A108971 27,28,29,37,36,35,34,33,32,31,30,40,41,42,43,44,45,46,38,39,47,48,49, %U A108971 57,56,55,54,53,52,51,50,60,61,62,63,64,65,66,58,59,67,68,69,77,76,75 %N A108971 Lexicographically earliest sequence such that in decimal representation sums of digits of consecutive terms differ exactly by 1 or -1. %C A108971 Permutation of the natural numbers with inverse A179977; A179978(n)=a(a(n)); A179979 gives fixed points: a(A179979(n))=A179979(n). %C A108971 abs(A007953(a(n+1)) - A007953(a(n))) = 1. %C A108971 A179987(n)=A007953(a(n)); A007953(a(A179988(n)))=n; a(A179988(n))=A051885(n+1). - _Reinhard Zumkeller_, Aug 09 2010, Jul 10 2011 %H A108971 R. Zumkeller, <a href="/A108971/b108971.txt">Table of n, a(n) for n = 1..10000</a> %H A108971 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %K A108971 nonn,base %O A108971 1,2 %A A108971 _Reinhard Zumkeller_, Jul 27 2005 %E A108971 Comment corrected and extended by _Reinhard Zumkeller_, Aug 04 2010