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 A080030 #7 Mar 30 2012 17:27:18 %S A080030 2,1,4,5,7,10,8,13,16,11,19,22,14,25,28,17,31,34,20,37,40,23,43,46,26, %T A080030 49,52,29,55,58,32,61,64,35,67,70,38,73,76,41,79,82,44,85,88,47,91,94, %U A080030 50,97,100,53,103,106,56,109,112,59,115,118,62,121,124,65,127,130,68 %N A080030 a(n) is taken to be the smallest positive integer not already present which is consistent with the condition "n is a member of the sequence if and only if a(n) is congruent to 1 mod 3". %C A080030 A permutation of all positive non-multiples of 3. - _Matthew Vandermast_, Mar 21 2003 %H A080030 B. Cloitre, N. J. A. Sloane and M. J. Vandermast, <a href="http://www.cs.uwaterloo.ca/journals/JIS/index.html">Numerical analogues of Aronson's sequence</a>, J. Integer Seqs., Vol. 6 (2003), #03.2.2. %H A080030 B. Cloitre, N. J. A. Sloane and M. J. Vandermast, <a href="http://arXiv.org/abs/math.NT/0305308">Numerical analogues of Aronson's sequence</a> (math.NT/0305308) %F A080030 a(3m)=3m+2, a(3m+1)=6m+1, a(3m+2)=6m+4. %Y A080030 Cf. A079000, A079313, A080029, A080031. %K A080030 easy,nonn %O A080030 0,1 %A A080030 _N. J. A. Sloane_, Mar 14 2003 %E A080030 More terms from _Matthew Vandermast_, Mar 21 2003