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A163888 a(n) = 2*a(n-2) for n > 2; a(1) = 5, a(2) = 4.

%I A163888 #11 Sep 08 2022 08:45:47
%S A163888 5,4,10,8,20,16,40,32,80,64,160,128,320,256,640,512,1280,1024,2560,
%T A163888 2048,5120,4096,10240,8192,20480,16384,40960,32768,81920,65536,163840,
%U A163888 131072,327680,262144,655360,524288,1310720,1048576,2621440,2097152,5242880
%N A163888 a(n) = 2*a(n-2) for n > 2; a(1) = 5, a(2) = 4.
%C A163888 Interleaving of A020714 and A000079 without initial terms 1 and 2.
%C A163888 Binomial transform is A163607, second binomial transform is A163608, third binomial transform is A163609, fourth binomial transform is A163610, fifth binomial transform is A163611.
%H A163888 G. C. Greubel, <a href="/A163888/b163888.txt">Table of n, a(n) for n = 1..1000</a>
%H A163888 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (0, 2).
%F A163888 a(n) = (7 - 3*(-1)^n)*2^((2*n-5+(-1)^n)/4).
%F A163888 G.f.: x*(5+4*x)/(1-2*x^2).
%t A163888 Transpose[NestList[{Last[#],2First[#]}&,{5,4},40]] [[1]]  (* _Harvey P. Dale_, Mar 14 2011 *)
%t A163888 LinearRecurrence[{0, 2},{5, 4},41] (* _Ray Chandler_, Aug 14 2015 *)
%o A163888 (Magma) [ n le 2 select 6-n else 2*Self(n-2): n in [1..41] ];
%o A163888 (PARI) x='x+O('x^50); vec(x*(5+4*x)/(1-2*x^2)) \\ _G. C. Greubel_, Aug 07 2017
%Y A163888 Cf. A020714 (5*2^n), A000079 (powers of 2), A163607, A163608, A163609, A163610, A163611.
%K A163888 nonn
%O A163888 1,1
%A A163888 _Klaus Brockhaus_, Aug 06 2009