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 A258439 #23 Nov 14 2024 00:07:05
%S A258439 1,1,3,2,9,4,27,8,81,16,243,32,729,64,2187,128,6561,256,19683,512,
%T A258439 59049,1024,177147,2048,531441,4096,1594323,8192,4782969,16384,
%U A258439 14348907,32768,43046721,65536,129140163,131072,387420489,262144,1162261467
%N A258439 Powers of 3 alternating with powers of 2.
%C A258439 a(n)*A098293(n) = A000400(floor(n/2)).
%H A258439 Colin Barker, <a href="/A258439/b258439.txt">Table of n, a(n) for n = 0..1000</a>
%H A258439 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (0,5,0,-6).
%F A258439 a(n) = ((5+(-1)^n)/2)^((2*n-1+(-1)^n)/4).
%F A258439 a(n) = 5*a(n-2)-6*a(n-4). - _Colin Barker_, May 30 2015
%F A258439 G.f.: -(3*x^3+2*x^2-x-1) / ((2*x^2-1)*(3*x^2-1)). - _Colin Barker_, May 30 2015
%p A258439 seq(op([3^n,2^n]),n=0..20); # _Muniru A Asiru_, Jul 16 2018
%t A258439 Flatten[Table[{3^n, 2^n}, {n, 0, 25}]] (* _Vincenzo Librandi_, Jul 17 2018 *)
%o A258439 (PARI) Vec(-(3*x^3+2*x^2-x-1)/((2*x^2-1)*(3*x^2-1)) + O(x^100)) \\ _Colin Barker_, May 30 2015
%o A258439 (GAP) Flat(List([0..20],n->[3^n,2^n])); # _Muniru A Asiru_, Jul 16 2018
%o A258439 (Magma) &cat[[3^n, 2^n]: n in [0..35]]; // _Vincenzo Librandi_, Jul 17 2018
%Y A258439 Cf. A098293, A006899.
%K A258439 nonn,easy
%O A258439 0,3
%A A258439 _Luce ETIENNE_, May 30 2015