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 A107285 #11 Jun 17 2025 00:43:40
%S A107285 4010,22055,202505,2007005,20052005,200502005,2005002005,20050002005,
%T A107285 200500002005,2005000002005,20050000002005,200500000002005,
%U A107285 2005000000002005,20050000000002005,200500000000002005,2005000000000002005,20050000000000002005,200500000000000002005
%N A107285 a(n) = 5*401*(10^n + 1).
%H A107285 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (11,-10).
%F A107285 a(n) = 2005*A062397(n).
%F A107285 From _Elmo R. Oliveira_, Jun 16 2025: (Start)
%F A107285 G.f.: 2005*(2-11*x)/((1-x)*(1-10*x)).
%F A107285 E.g.f.: 2005*exp(x)*(1 + exp(9*x)).
%F A107285 a(n) = 10*a(n-1) - 18045.
%F A107285 a(n) = 11*a(n-1) - 10*a(n-2). (End)
%e A107285 a(4) = 5*401*10001 = 20052005 = A106605(38).
%t A107285 2005(10^Range[0,20]+1) (* or *) LinearRecurrence[{11,-10},{4010,22055},20] (* _Harvey P. Dale_, Sep 06 2016 *)
%o A107285 (PARI) my(x='x+O('x^18)); Vec(2005*(2-11*x)/((10*x-1)*(x-1))) \\ _Elmo R. Oliveira_, Jun 16 2025
%Y A107285 Cf. A062397, A106605.
%K A107285 nonn,easy
%O A107285 0,1
%A A107285 _Reinhard Zumkeller_, May 20 2005
%E A107285 More terms from _Elmo R. Oliveira_, Jun 16 2025