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 A133806 #4 Jul 16 2015 06:40:52 %S A133806 0,1,1,2,2,4,3,8,5,16,10,32,21,64,43,128,86,256,171,512,341,1024,682, %T A133806 2048,1365,4096,2731,8192,5462,16384,10923,32768,21845,65536,43690, %U A133806 131072,87381,262144,174763,524288,349526,1048576,699051,2097152 %N A133806 Alternate terms of A131708 and A000079. %H A133806 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (0,3,0,-3,0,2). %F A133806 G.f.: -x*(1+x-x^2-x^3+x^4) / ( (2*x^2-1)*(x^4-x^2+1) ). - _R. J. Mathar_, Jul 16 2015 %Y A133806 Cf. A000079. %K A133806 nonn,easy %O A133806 0,4 %A A133806 _Paul Curtz_, Jan 06 2008