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 A077917 #19 Jan 27 2019 05:42:46 %S A077917 1,-1,5,-11,33,-87,241,-655,1793,-4895,13377,-36543,99841,-272767, %T A077917 745217,-2035967,5562369,-15196671,41518081,-113429503,309895169, %U A077917 -846649343,2313089025,-6319476735,17265131521,-47169216511,128868696065,-352075825151,961889042433,-2627929735167 %N A077917 Expansion of (1-x)^(-1)/(1+2*x-2*x^2). %C A077917 Pisano period lengths: 1, 1, 6, 1, 24, 6, 48, 1, 18, 24, 5, 6, 12, 48, 24, 1,144, 18,180, 24,... - _R. J. Mathar_, Aug 10 2012 %H A077917 P. Z. Chinn, R. Grimaldi and S. Heubach, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL10/Heubach/heubach40.html">Tiling with Ls and Squares</a>, J. Int. Sequences 10 (2007) #07.2.8. %H A077917 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (-1,4,-2) %F A077917 a(n+1)-a(n) = (-1)^(n+1)*A002605(n+2). - _R. J. Mathar_, Mar 14 2011 %o A077917 (PARI) Vec((1-x)^(-1)/(1+2*x-2*x^2)+O(x^99)) \\ _Charles R Greathouse IV_, Sep 24 2012 %K A077917 sign,easy %O A077917 0,3 %A A077917 _N. J. A. Sloane_, Nov 17 2002