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 A180077 #8 Aug 11 2014 22:45:44 %S A180077 0,1,3,5,2,7,11,4,9,13,6,19,15,23,27,49,8,21,17,12,25,29,37,43,33,10, %T A180077 47,58,14,99,56,62,31,39,20,45,35,16,93,127,24,60,106,28,75,143,50,64, %U A180077 71,79,41,95,22,68,129,18,164,148,120,112,141,26,110,108,30,89,77,38,91,52 %N A180077 Inverse permutation to A180076. %C A180077 A180079(n) = a(a(n)); %C A180077 a(A180078(n)) = A180078(a(n)) = A180076(n). %H A180077 Reinhard Zumkeller, <a href="/A180077/b180077.txt">Table of n, a(n) for n = 0..10000</a> %H A180077 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %o A180077 (Haskell) %o A180077 import Data.List (elemIndex); import Data.Maybe (fromJust) %o A180077 a180077 = fromJust . (`elemIndex` a180076_list) %o A180077 -- _Reinhard Zumkeller_, Mar 13 2014 %K A180077 nonn %O A180077 0,3 %A A180077 _Reinhard Zumkeller_, Aug 14 2010