%I #13 Sep 08 2022 08:46:00

%S 4,22,148,1030,7204,50422,352948,2470630,17294404,121060822,847425748,

%T 5931980230,41523861604,290667031222,2034669218548,14242684529830,

%U 99698791708804,697891541961622,4885240793731348,34196685556119430

%N 3*7^n+1.

%H Vincenzo Librandi, <a href="/A199418/b199418.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (8,-7).

%F a(n) = 7*a(n-1)-6.

%F a(n) = 8*a(n-1)-7*a(n-2).

%F G.f.: 2*(2-5*x)/((1-x)*(1-7*x)).

%t LinearRecurrence[{8,-7},{4,22},20] (* _Harvey P. Dale_, Dec 29 2018 *)

%o (Magma) [3*7^n+1: n in [0..30]];

%K nonn,easy

%O 0,1

%A _Vincenzo Librandi_, Nov 06 2011