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 A086961 #6 Mar 30 2012 18:50:37 %S A086961 3,1,2,8,25,4,21,6,15,5,33,9,39,7,12,24,51,36,57,16,14,11,69,20,10,13, %T A086961 54,56,87,18,93,48,22,17,280,30,111,19,26,32,123,28,129,88,27,23,141, %U A086961 40,343,70,34,104,159,45,275,42,38,29,177,50,183,31,168,112,325 %N A086961 a(A086957(n))=A086959(n), a(A086958(n))=A086957(n), a(A086959(n))=A086958(n), see A086956. %C A086961 permutation of natural numbers with inverse A086960: a(A086960(n)) = A086960(a(n)) = n; %C A086961 a(n) = A086962(A086963(n)) = A086963(A086962(n)). %H A086961 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %Y A086961 Cf. A086572, A086571. %K A086961 nonn %O A086961 1,1 %A A086961 _Reinhard Zumkeller_, Jul 25 2003