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 A171513 #7 Dec 15 2017 17:37:10 %S A171513 10,181,10801,1008001,100080001,10000800001,1000008000001, %T A171513 100000080000001,10000000800000001,1000000008000000001, %U A171513 100000000080000000001,10000000000800000000001 %N A171513 1+8*10^n+100^n. %H A171513 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (111,-1110,1000) %F A171513 From _Chai Wah Wu_, May 30 2016: (Start) %F A171513 a(n) = 111*a(n-1) - 1110*a(n-2) + 1000*a(n-3) for n > 2. %F A171513 G.f.: (1810*x^2 - 929*x + 10)/((1 - x)*(1 - 10*x)*(1 - 100*x)). (End) %F A171513 E.g.f.: (1 + 8*exp(9*x) + exp(99*x))*exp(x). - _Ilya Gutkovskiy_, May 30 2016 %K A171513 easy,nonn %O A171513 0,1 %A A171513 _Jason Earls_, Dec 10 2009