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 A171375 #9 Dec 15 2017 17:37:09
%S A171375 5,131,10301,1003001,100030001,10000300001,1000003000001,
%T A171375 100000030000001,10000000300000001,1000000003000000001,
%U A171375 100000000030000000001,10000000000300000000001,1000000000003000000000001,100000000000030000000000001,10000000000000300000000000001
%N A171375 1+3*10^n+100^n.
%H A171375 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (111,-1110,1000)
%F A171375 From _Chai Wah Wu_, May 30 2016: (Start)
%F A171375 a(n) = 111*a(n-1) - 1110*a(n-2) + 1000*a(n-3) for n > 2.
%F A171375 G.f.: (1310*x^2 - 424*x + 5)/((1 - x)*(1 - 10*x)*(1 - 100*x)). (End)
%F A171375 E.g.f.: (1 + 3*exp(9*x) + exp(99*x))*exp(x). - _Ilya Gutkovskiy_, May 30 2016
%t A171375 LinearRecurrence[{111,-1110,1000},{5,131,10301},20] (* _Harvey P. Dale_, Jun 03 2016 *)
%K A171375 easy,nonn
%O A171375 0,1
%A A171375 _Jason Earls_, Dec 07 2009
%E A171375 More terms from _Harvey P. Dale_, Jun 03 2016