%I A025169
%S A025169 2,6,16,42,110,288,754,1974,5168,13530,35422,92736,242786,635622,
%T A025169 1664080,4356618,11405774,29860704,78176338,204668310,535828592,
%U A025169 1402817466,3672623806,9615053952,25172538050,65902560198,172535142544
%N A025169 a(n)=2F(2n+2), where F=A000045 (the Fibonacci sequence).
%H A025169 <a href="Sindx_Rea.html#recLCC">Index entries for sequences related to 
               linear recurrences with constant coefficients</a>
%H A025169 Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/
               RecursiveSequences.html">Recursive Sequences</a>
%F A025169 G.f.: 2/(1-3x+x^2). a(n)=3a(n-1)-a(n-2).
%o A025169 (PARI) a(n)=2*fibonacci(2*n+2)
%o A025169 (Other) sage: [lucas_number2(n,2,1)*lucas_number1(n,3,1) for n in xrange(1, 
               28)]# [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Nov 15 
               2009]
%Y A025169 A025169(n)=2*A001906(n+1).
%Y A025169 Sequence in context: A152089 A102699 A156664 this_sequence A111282 A115730 
               A003142
%Y A025169 Adjacent sequences: A025166 A025167 A025168 this_sequence A025170 A025171 
               A025172
%K A025169 nonn,new
%O A025169 0,1
%A A025169 w.meeussen (wouter.meeussen(AT)pandora.be)
%E A025169 Better description from Michael Somos