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 A076905 #5 Mar 30 2012 18:39:10 %S A076905 1,1,2,2,3,4,4,5,5,6,7,7,8,8,9,9,10,10,11,12,12,13,13,14,14,15,16,16, %T A076905 17,17,18,18,19,19,20,21,21,22,22,23,23,24,25,25,26,26,27,28,28,29,29, %U A076905 30,30,31,32,32,33,33,34,34,35,35,36,37,37,38,38,39,39,40,41,41,42,42 %N A076905 a(1)=1, a(n)=n-a(n-1)+a(a(n-1))-a(a(a(n-1))). %F A076905 Conjecture: let c be the real root of 1-2*x+x^2-x^3, c=0.5698402909980532659113..., then a(n)=floor(cn) +0 /+ 1 %K A076905 nonn %O A076905 1,3 %A A076905 _Benoit Cloitre_, Nov 27 2002