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 A190017 #16 Oct 26 2019 02:39:50 %S A190017 1,1113,2224,3335,4446,5557,6668,7779,8890,2,114,225,336,447,558,669, %T A190017 780,891,1002,1114,1225,1336,1447,1558,1669,1780,1891,2002,2113,2225, %U A190017 2336,2447,2558,2669,2780,2891,3002,3113,3224,3336,3447,3558,3669,3780,3891 %N A190017 Inverse permutation to A190016: lexicographical ordering of integers 1 .. 10^4. %C A190017 a(A190016(n)) = A190016(a(n)) = n. %H A190017 Reinhard Zumkeller, <a href="/A190017/b190017.txt">Table of n, a(n) for n = 1..10000</a> (full sequence) %o A190017 (Haskell) %o A190017 import Data.List (elemIndex) %o A190017 import Data.Maybe (fromJust) %o A190017 a190017 n = a190017_list !! (n-1) %o A190017 a190017_list = %o A190017 map (succ . fromJust . (`elemIndex` a190016_list)) [1..10000] %o A190017 (PARI) A190017=vecsort(A190016=vecsort(vector(10^4,n,Str(n)),,1),,1) \\ _M. F. Hasler_, Oct 26 2019 %Y A190017 Cf. A190016 (inverse: integers 1..10^4 in lexicographical order). %Y A190017 Cf. A119589, A119590 (integers 1..100 in lexicographical order, and inverse). %K A190017 nonn,base,fini,full %O A190017 1,2 %A A190017 _Reinhard Zumkeller_, May 06 2011