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 A180078 #4 Mar 30 2012 18:51:06 %S A180078 0,1,7,4,5,2,25,3,37,16,20,10,11,8,43,19,22,55,241,6,73,18,69,9,100, %T A180078 34,124,28,23,17,47,97,77,40,72,109,190,52,214,24,88,46,259,13,481,36, %U A180078 42,61,49,12,106,105,160,182,148,415,64,68,14,223,50,394,32,115,26,181,48 %N A180078 A180076(A180076(n)). %C A180078 Permutation of the natural numbers with inverse A180079; %C A180078 a(A180077(n)) = A180077(a(n)) = A180076(n). %H A180078 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %K A180078 nonn %O A180078 0,3 %A A180078 _Reinhard Zumkeller_, Aug 14 2010