A199487 - OEIS

%I #17 Jun 30 2026 21:52:56

%S 10,64,442,3088,21610,151264,1058842,7411888,51883210,363182464,

%T 2542277242,17795940688,124571584810,872001093664,6104007655642,

%U 42728053589488,299096375126410,2093674625884864,14655722381194042,102590056668358288

%N a(n) = 9*7^n+1.

%H Vincenzo Librandi, <a href="/A199487/b199487.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*(5-8*x)/((1-x)*(1-7*x)).

%t (9*7^Range[0,20])+1 (* _Harvey P. Dale_, May 10 2014 *)

%t (* Alternative: *)

%t LinearRecurrence[{8,-7},{10,64},20] (* _Harvey P. Dale_, May 10 2014 *)

%o (Magma) [9*7^n+1: n in [0..30]];

%K nonn,easy,changed

%O 0,1

%A _Vincenzo Librandi_, Nov 07 2011