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 A258225 #10 Jun 26 2015 18:53:16
%S A258225 7,4,1,8,5,2,9,6,3,70,37,104,71,38,105,72,39,106,73,40,107,74,41,108,
%T A258225 75,42,109,76,43,10,77,44,11,78,45,12,79,46,13,80,47,14,81,48,15,82,
%U A258225 49,16,83,50,17,84,51,18,85,52,19,86,53,20,87,54,21,88,55
%N A258225 a(n) = A258083(n) / 3.
%C A258225 Permutation of the positive integers, inverse: A258226.
%H A258225 Reinhard Zumkeller, <a href="/A258225/b258225.txt">Table of n, a(n) for n = 1..9999</a>
%H A258225 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%o A258225 (Haskell)
%o A258225 a258225 = flip div 3 . a258083
%o A258225 (PARI) lista(nn) = {v = []; vs = vecsort(v); for (n=1, nn, k=3; pt = 10^(#digits(n)); while (! (((k % pt) == n) && !vecsearch(vs, k)), k+=3); v = concat(v, k); vs = vecsort(v); print1(k/3, ", "););} \\ _Michel Marcus_, Jun 26 2015
%Y A258225 Cf. A258083, A258226, A258329, A258334.
%K A258225 nonn,base
%O A258225 1,1
%A A258225 _Reinhard Zumkeller_, May 27 2015