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 A245804 #30 Apr 01 2025 17:34:40
%S A245804 -1,0,6,30,114,390,1266,3990,12354,37830,115026,348150,1050594,
%T A245804 3164070,9516786,28599510,85896834,257887110,774054546,2322950070,
%U A245804 6970423074,20914414950,62749536306,188261191830,564808741314,1694476555590,5083530330066,15250792316790
%N A245804 a(n) = 2*3^n - 3*2^n.
%C A245804 Essentially 2 * A210448. - _Joerg Arndt_, Aug 03 2014
%H A245804 Vincenzo Librandi, <a href="/A245804/b245804.txt">Table of n, a(n) for n = 0..1000</a>
%H A245804 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (5,-6).
%F A245804 G.f.: (-1 +5*x)/((1-2*x)(1-3*x)).
%F A245804 a(n) = 5*a(n-1) -6*a(n-2) for n>1.
%F A245804 a(n) = A008776(n) - A007283(n). - _Michel Marcus_, Aug 03 2014
%t A245804 CoefficientList[Series[(-1 + 5 x)/((1 - 2 x) (1 - 3 x)), {x, 0, 30}], x]
%t A245804 Table[(2 3^n - 3 2^n), {n, 0, 30}] (* _Vincenzo Librandi_, Aug 04 2014 *)
%o A245804 (Magma) [2*3^n-3*2^n: n in [0..40]];
%o A245804 (Magma) I:=[-1,0]; [n le 2 select I[n] else 5*Self(n-1)-6*Self(n-2): n in [1..30]];
%Y A245804 Cf. A007283, A008776.
%K A245804 sign,easy
%O A245804 0,3
%A A245804 _Vincenzo Librandi_, Aug 03 2014