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 A098609 #19 Sep 09 2024 15:13:19
%S A098609 0,99,9999,999999,99999999,9999999999,999999999999,99999999999999,
%T A098609 9999999999999999,999999999999999999,99999999999999999999,
%U A098609 9999999999999999999999,999999999999999999999999,99999999999999999999999999,9999999999999999999999999999,999999999999999999999999999999
%N A098609 a(n) = 100^n - 1.
%H A098609 Vincenzo Librandi, <a href="/A098609/b098609.txt">Table of n, a(n) for n = 0..100</a>
%H A098609 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (101,-100).
%F A098609 a(n) = 100*a(n-1) + 99 = A002283(2*n) = A098608(n) - 1.
%F A098609 From _Chai Wah Wu_, Sep 22 2016: (Start)
%F A098609 a(n) = 101*a(n-1) - 100*a(n-2) for n > 1.
%F A098609 G.f.: 99*x/((x - 1)*(100*x - 1)). (End)
%F A098609 E.g.f.: exp(x)*(exp(99*x) - 1). - _Stefano Spezia_, Aug 05 2024
%F A098609 a(n) = A002283(n)*A062397(n). - _Elmo R. Oliveira_, Sep 09 2024
%t A098609 Table[100^n - 1, {n, 0, 20}] (* _Vincenzo Librandi_, Sep 23 2016 *)
%o A098609 (Magma) [100^n-1: n in [0..20]]; // _Vincenzo Librandi_, Sep 23 2016
%Y A098609 Cf. A002283, A062397, A098608.
%K A098609 easy,nonn
%O A098609 0,2
%A A098609 _Henry Bottomley_, Sep 17 2004