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 A118765 #6 Mar 30 2012 18:50:54 %S A118765 0,1,2,3,4,5,6,7,8,9,18,19,10,11,12,13,14,15,16,17,27,28,20,21,22,23, %T A118765 24,25,26,29,38,39,30,31,32,33,34,35,36,37,47,48,40,41,42,43,44,45,46, %U A118765 49,58,59,50,51,52,53,54,55,56,57,67,68,60,61,62,63,64,65,66,69,78,79,70 %N A118765 A118763(A118763(n)). %C A118765 Inverse integer permutation of A118766; %C A118765 A118764(a(n)) = a(A118764(n)) = A118763(n). %H A118765 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %Y A118765 Cf. A118766. %K A118765 nonn %O A118765 0,3 %A A118765 _Reinhard Zumkeller_, May 01 2006