%I #13 Sep 09 2018 04:08:56

%S 1,7,57,495,4401,39447,354537,3189375,28700001,258286887,2324542617,

%T 20920765455,188286534801,1694577750327,15251196564297,

%U 137260759512735,1235346806916801,11118121176157767,100063090327139577,900567812169415215

%N a(n) = (2*9^n + 3^n)/3.

%C Binomial transform of A082412.

%H Nathaniel Johnston, <a href="/A082413/b082413.txt">Table of n, a(n) for n = 0..250</a>

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (12,-27).

%F G.f.: (1-5*x)/((1-3*x)*(1-9*x));

%F E.g.f.: (2*exp(9*x) + exp(3*x))/3.

%F a(n) = (2*9^n + 3^n)/3.

%p seq((2*9^n+3^n)/3,n=0..19); # _Nathaniel Johnston_, Jun 26 2011

%Y Cf. A082412, A082414.

%K easy,nonn

%O 0,2

%A _Paul Barry_, Apr 23 2003