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 A014447 #19 Jun 13 2015 00:48:35 %S A014447 1,3,7,11,29,47,123,199,521,843,2207,3571,9349,15127,39603,64079, %T A014447 167761,271443,710647,1149851,3010349,4870847,12752043,20633239, %U A014447 54018521,87403803,228826127,370248451,969323029,1568397607,4106118243 %N A014447 Odd Lucas numbers. %C A014447 Lucas(3n+1) union Lucas(3n+2). %H A014447 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (0,4,0,1) %F A014447 a(n) = 4*a(n-2)+a(n-4). - R. J. Mathar, Feb 10 2011 %F A014447 G.f.: (-x^3 + 3*x^2 + 3*x + 1)/(-x^4 - 4*x^2 + 1). - _Ralf Stephan_, Aug 31 2013 %t A014447 Select[LucasL[Range[50]],OddQ] (* _Harvey P. Dale_, Sep 26 2012 *) %K A014447 nonn,easy %O A014447 0,2 %A A014447 _Mohammad K. Azarian_ %E A014447 More terms from _Erich Friedman_.