%I #17 Sep 08 2022 08:44:48

%S 1,9,96,991,9984,99975,999964,9999951,99999936,999999919,9999999900,

%T 99999999879,999999999856,9999999999831,99999999999804,

%U 999999999999775,9999999999999744,99999999999999711,999999999999999676

%N a(n) = 10^n - n^2.

%H Vincenzo Librandi, <a href="/A024116/b024116.txt">Table of n, a(n) for n = 0..300</a>

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (13,-33,31,-10).

%F G.f.: (1-4*x+12*x^2+9*x^3)/((1-10*x)*(1-x)^3). - _Vincenzo Librandi_, Oct 06 2014

%F a(n) = 13*a(n-1) -33*a(n-2) +31*a(n-3) -10*a(n-4) for n>3. - _Vincenzo Librandi_, Oct 06 2014

%F a(n) = A011557(n) - A000290(n). - _Michel Marcus_, Oct 06 2014

%t Table[10^n - n^2, {n, 0, 25}] (* or *) CoefficientList[Series[(1 - 4 x + 12 x^2 + 9 x^3)/((1 - 10 x) (1-x)^3), {x, 0, 30}], x] (* _Vincenzo Librandi_, Oct 06 2014 *)

%t LinearRecurrence[{13,-33,31,-10},{1,9,96,991},20] (* _Harvey P. Dale_, May 29 2021 *)

%o (Magma) [10^n-n^2: n in [0..20]]; // _Vincenzo Librandi_, Jun 30 2011

%Y Cf. similar sequences listed in A024025.

%K nonn,easy

%O 0,2

%A _N. J. A. Sloane_.