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 A081688 #10 Nov 23 2014 03:45:33
%S A081688 0,1,3,4,5,7,8,9,10,12,13,14,15,16,18,19,20,21,22,23,24,26,27,28,29,
%T A081688 30,31,32,33,35,36,37,38,39,40,41,42,43,45,46,47,48,49,50,51,52,53,54,
%U A081688 56,57,58,59,60,61,62,63,64,65,66,67,69,70,71,72,73,74,75,76,77
%N A081688 0 followed by A030124 - 1.
%C A081688 From P-positions in a certain game.
%C A081688 The rule "monotonically increasing sequence where the size of each run of consecutive integers is given by the sequence itself" produces this sequence without the initial 0. - _Eric Angelini_, Aug 19 2008
%H A081688 A. S. Fraenkel, <a href="http://www.wisdom.weizmann.ac.il/~fraenkel/">Home Page</a>
%H A081688 A. S. Fraenkel, <a href="http://www.emis.de/journals/INTEGERS/papers/eg6/eg6.Abstract.html">New games related to old and new sequences</a>, INTEGERS, Electronic J. of Combinatorial Number Theory, Vol. 4, Paper G6, 2004.
%F A081688 Let a(n) = this sequence, b(n) = A081689. Then a(n) = mex{ a(i), b(i) : 0 <= i < n}, b(n) = b(n-1) + a(n) + 1. Apart from initial zero, complement of A081689.
%Y A081688 Cf. A030124, A005228, A081689.
%K A081688 nonn
%O A081688 0,3
%A A081688 _N. J. A. Sloane_, Apr 02 2003