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 A190127 #11 Jul 13 2013 12:03:52 %S A190127 1,2,5906,3,3859,5907,7954,4,2051,3860,4883,5908,6931,7955,8978,5, %T A190127 1028,2052,3075,3861,4372,4884,5395,5909,6420,6932,7443,7956,8467, %U A190127 8979,9490,6,517,1029,1540,2053,2564,3076,3587,3862,4117,4373,4628,4885,5140,5396 %N A190127 Inverse permutation to A190126. %C A190127 a(A190126(n)) = A190126(a(n)) = n. %H A190127 Reinhard Zumkeller, <a href="/A190127/b190127.txt">Table of n, a(n) for n = 1..10000</a> (full sequence) %o A190127 (Haskell) %o A190127 import Data.List (elemIndex) %o A190127 import Data.Maybe (fromJust) %o A190127 a190127 n = a190127_list !! (n-1) %o A190127 a190127_list = %o A190127 map (succ . fromJust . (`elemIndex` a190126_list)) [1..10000] %K A190127 nonn,base,fini,full %O A190127 1,2 %A A190127 _Reinhard Zumkeller_, May 06 2011