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%I #21 Mar 02 2022 12:08:51
%S 1,4,34,280,2146,15784,113554,807160,5699266,40091464,281426674,
%T 1973132440,13824509986,96821901544,677954637394,4746487768120,
%U 33228635602306,232613334118024,1628344878433714,11398620307466200
%N a(n) = 7^n-4^n+1^n.
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (12,-39,28).
%F G.f.: 1/(1-7*x)-1/(1-4*x)+1/(1-x). E.g.f.: e^(7*x)-e^(4*x)+e^x.
%F a(n) = 11*a(n-1)-28*a(n-2)+18 with a(0)=1, a(1)=4. - _Vincenzo Librandi_, Jul 21 2010
%t Table[7^n-4^n+1,{n,0,20}] (* or *) LinearRecurrence[{12,-39,28},{1,4,34},20] (* _Harvey P. Dale_, Jul 16 2017 *)
%o (PARI) a(n)=7^n-4^n+1 \\ _Charles R Greathouse IV_, Sep 24 2015
%Y Cf. A155596, A155597, A155598, A155599, A155600, A155601, A155622, A155623, A155624, A155625, A155626, A155627.
%K nonn,easy
%O 0,2
%A _Mohammad K. Azarian_, Jan 30 2009
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