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 A246059 #13 May 07 2025 00:49:41
%S A246059 1,18,188,1888,18888,188888,1888888,18888888,188888888,1888888888,
%T A246059 18888888888,188888888888,1888888888888,18888888888888,
%U A246059 188888888888888,1888888888888888,18888888888888888,188888888888888888,1888888888888888888,18888888888888888888,188888888888888888888
%N A246059 a(n) = (17*10^n - 8)/9.
%H A246059 Vincenzo Librandi, <a href="/A246059/b246059.txt">Table of n, a(n) for n = 0..100</a>
%H A246059 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (11,-10).
%F A246059 G.f.: (1 + 7*x)/((1 - x)*(1 - 10*x)).
%F A246059 a(n) = 11*a(n-1) - 10*a(n-2).
%F A246059 E.g.f.: exp(x)*(17*exp(9*x) - 8)/9. - _Elmo R. Oliveira_, May 06 2025
%t A246059 Table[(17 10^n - 8)/9, {n, 0, 20}]
%o A246059 (Magma) [(17*10^n-8)/9: n in [0..20]];
%Y A246059 Cf. similar sequences listed in A246057.
%K A246059 nonn,easy
%O A246059 0,2
%A A246059 _Vincenzo Librandi_, Aug 13 2014