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%I #18 Sep 08 2022 08:45:10
%S 1,8,100,800,10000,80000,1000000,8000000,100000000,800000000,
%T 10000000000,80000000000,1000000000000,8000000000000,100000000000000,
%U 800000000000000,10000000000000000,80000000000000000
%N a(n) = (9*10^n + (-10)^n)/10.
%H Vincenzo Librandi, <a href="/A083227/b083227.txt">Table of n, a(n) for n = 0..200</a>
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (0,100).
%F a(n) = (9*10^n + (-10)^n)/10.
%F G.f.: (1+8*x)/((1+10*x)*(1-10*x)).
%F E.g.f.: (9*exp(10*x) + exp(-10*x))/10.
%t LinearRecurrence[{0,100},{1,8},20] (* _Harvey P. Dale_, Jun 02 2019 *)
%o (Magma) [(9*10^n+(-10)^n)/10: n in [0..25]]; // _Vincenzo Librandi_, Jun 29 2011
%o (PARI) a(n)= (9*10^n+(-10)^n)/10 \\ _Charles R Greathouse IV_, Jun 29 2011
%Y Cf. A083226.
%K easy,nonn
%O 0,2
%A _Paul Barry_, Apr 23 2003