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 A129677 #15 Mar 18 2022 21:52:07
%S A129677 2,6,1,4,3,5,8,12,7,9,11,10,14,20,13,16,15,17,19,18,22,24,21,23,26,30,
%T A129677 25,28,27,29,32,36,31,33,35,34,38,40,37,39,42,48,41,44,43,45,47,46,50,
%U A129677 54,49,52,51,53,56,60,55,57,59,58,62,68,61,64,63,65,67,66,70,72,69,71
%N A129677 Inverse permutation to A129676.
%C A129677 The inversion maintains the cyclic characteristics described in A129676.
%H A129677 Ferenc Adorjan, <a href="/A129677/b129677.txt">Table of n, a(n) for n = 1..10000</a>
%H A129677 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%o A129677 (PARI) {pinverse(v)= /* Permutation inverse of a positive sequence */
%o A129677 local(n,m,x);n=matsize(v)[2]; x=vector(n);
%o A129677 for(i=1,n,if(v[i]<=n,x[v[i]]=i)); return(x)}
%o A129677 a=pinverse(A129676)
%Y A129677 Inverse of A129676, cf. A128754, A128755, A129681 and A000069.
%K A129677 nonn,base
%O A129677 1,1
%A A129677 Ferenc Adorjan (fadorjan(AT)freemail.hu or ferencadorjan(AT)gmail.com), May 01 2007