This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A179980 #22 Apr 08 2024 12:44:17
%S A179980 1,8,83,826,8265,82644,826447,8264462,82644629,826446280,8264462811,
%T A179980 82644628098,826446280993,8264462809916,82644628099175,
%U A179980 826446280991734,8264462809917357,82644628099173552,826446280991735539,8264462809917355370,82644628099173553721
%N A179980 a(n) = 10*a(n-1) - (-1)^n * n, a(1) = 1.
%H A179980 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (8,19,10).
%F A179980 From _R. J. Mathar_, Aug 06 2010: (Start)
%F A179980 a(n) = +8*a(n-1) +19*a(n-2) +10*a(n-3).
%F A179980 G.f.: -x/((10*x-1)*(1+x)^2).
%F A179980 a(n) = (10^(n+1) -11*n*(-1)^n -10*(-1)^n)/121. (End)
%t A179980 LinearRecurrence[{8,19,10},{1,8,83},20] (* _Harvey P. Dale_, Nov 17 2014 *)
%Y A179980 Cf. A007908, A021125.
%K A179980 nonn,easy
%O A179980 1,2
%A A179980 _Mark Dols_, Aug 04 2010