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 A077865 #11 May 21 2018 15:21:28 %S A077865 1,2,5,9,18,32,60,107,196,351,637,1144,2068,3720,6713,12086,21793, %T A077865 39253,70754,127468,229724,413907,745888,1343979,2421849,4363920, %U A077865 7863640,14169632,25532993,46008618,82904973,149389217,269190546,485064008,874055884,1574993355 %N A077865 Expansion of (1-x)^(-1)/(1-x-2*x^2+x^3). %C A077865 a(n-1)=R(n) for n>=1, where R(n) is the number of 01-words of length n in which all runlengths of 1's are odd. Example: R(3) counts 001,010,100,101,111. - _Clark Kimberling_, Jun 26 2004 %D A077865 Clark Kimberling, Binary words with restricted repetitions and associated compositions of integers, in Applications of Fibonacci Numbers, vol.10, Proceedings of the Eleventh International Conference on Fibonacci Numbers and Their Applications, William Webb, editor, Congressus Numerantium, Winnipeg, Manitoba 194 (2009) 141-151. %H A077865 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (2,1,-3,1) %F A077865 a(n)=a(n-1)+2a(n-2)-a(n-3)+1 for n>=3. a(n)=2a(n-1)+a(n-2)-3a(n-3)+a(n-4) for n>=4. - _Clark Kimberling_, Jun 26 2004 %o A077865 (PARI) Vec((1-x)^(-1)/(1-x-2*x^2+x^3)+O(x^99)) \\ _Charles R Greathouse IV_, Sep 26 2012 %K A077865 nonn,easy %O A077865 0,2 %A A077865 _N. J. A. Sloane_, Nov 17 2002