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a(n) = 8*((9*n + 8)*10^n - 8)/81.
3

%I #24 Aug 19 2018 12:28:02

%S 0,16,256,3456,43456,523456,6123456,70123456,790123456,8790123456,

%T 96790123456,1056790123456,11456790123456,123456790123456,

%U 1323456790123456,14123456790123456,150123456790123456,1590123456790123456,16790123456790123456,176790123456790123456

%N a(n) = 8*((9*n + 8)*10^n - 8)/81.

%H Colin Barker, <a href="/A294329/b294329.txt">Table of n, a(n) for n = 0..900</a>

%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (21,-120,100).

%F a(n) = (8/9) * A294327(n) = 8 * A294328(n).

%F From _Colin Barker_, Oct 28 2017: (Start)

%F G.f.: 16*x*(1 - 5*x) / ((1 - x)*(1 - 10*x)^2).

%F a(n) = 21*a(n-1) - 120*a(n-2) + 100*a(n-3) for n>2.

%F (End)

%t LinearRecurrence[{21,-120,100},{0,16,256},20] (* _Harvey P. Dale_, Aug 19 2018 *)

%o (PARI) concat(0, Vec(16*x*(1 - 5*x) / ((1 - x)*(1 - 10*x)^2) + O(x^30))) \\ _Colin Barker_, Oct 28 2017

%Y Cf. A294327, A294328.

%K nonn,easy

%O 0,2

%A _Seiichi Manyama_, Oct 28 2017