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 A165149 #15 Mar 21 2023 18:35:06
%S A165149 1,11,109,1031,9529,87011,789349,7135391,64374769,580154171,
%T A165149 5225293789,47047175351,423522234409,3812188390931,34312136924629,
%U A165149 308821439352911,2779453989332449,25015391079773291,225140045596865869,2026268039766324071,18236450504869572889,164128245278689437251
%N A165149 a(n) = (3*9^n - 5^n)/2.
%C A165149 Binomial transform of A165148. Inverse binomial transform of A165150.
%H A165149 Vincenzo Librandi, <a href="/A165149/b165149.txt">Table of n, a(n) for n = 0..200</a>
%H A165149 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (14,-45).
%F A165149 a(n) = 14*a(n-1) - 45*a(n-2) for n > 1; a(0) = 1, a(1) = 11.
%F A165149 G.f.: (1 - 3*x)/((1 - 5*x)*(1 - 9*x)).
%F A165149 E.g.f.: exp(5*x)*(3*exp(4*x) - 1)/2. - _Stefano Spezia_, Mar 21 2023
%p A165149 A165149:=n->(3*9^n-5^n)/2; seq(A165149(n), n=0..30); # _Wesley Ivan Hurt_, Dec 10 2013
%t A165149 Table[(3*9^n - 5^n)/2, {n, 0, 30}] (* _Wesley Ivan Hurt_, Dec 10 2013 *)
%o A165149 (Magma) [ (3*9^n-5^n)/2: n in [0..18] ];
%Y A165149 Cf. A165148, A165150.
%K A165149 nonn,easy
%O A165149 0,2
%A A165149 _Klaus Brockhaus_, Sep 15 2009