%I A055849
%S A055849 1,9,26,69,181,474,1241,3249,8506,22269,58301,152634,399601,1046169,
%T A055849 2738906,7170549,18772741,49147674,128670281,336863169,881919226,
%U A055849 2308894509,6044764301,15825398394,41431430881,108468894249
%N A055849 a(n)=3a(n-1)-a(n-2); a(0)=1, a(1)=9.
%D A055849 A. H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, 
               pps. 194-196.
%H A055849 <a href="Sindx_Rea.html#recLCC">Index entries for sequences related to 
               linear recurrences with constant coefficients</a>
%H A055849 Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/
               RecursiveSequences.html">Recursive Sequences</a>
%F A055849 a(n)={9*[((3+sqrt(5))/2)^n-((3-sqrt(5))/2)^n]-[((3+sqrt(5))/2)^(n-1)-((3-sqrt(5))/
               2)^(n-1)]}/sqrt(5).
%F A055849 G.f.(x)=(1+6x)/(1-3x+x^2).
%Y A055849 Sequence in context: A052153 A048468 A048771 this_sequence A084813 A056409 
               A056399
%Y A055849 Adjacent sequences: A055846 A055847 A055848 this_sequence A055850 A055851 
               A055852
%K A055849 easy,nonn
%O A055849 0,2
%A A055849 Barry E. Williams, Jun 03 2000