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 A016215 #21 Jul 08 2025 05:43:49
%S A016215 1,14,153,1570,15821,158574,1586833,15871610,158725941,1587288934,
%T A016215 15872977913,158730044850,1587301245661,15873014848094,
%U A016215 158730155655393,1587301578077290,15873015845342981,158730158647140054,1587301587052531273,15873015872268704930
%N A016215 Expansion of 1 / ((1-x) * (1-3*x) * (1-10*x)).
%H A016215 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (14,-43,30).
%F A016215 a(0)=1, a(1)=14, a(n)=13*a(n-1)-30*a(n-2)+1. - _Vincenzo Librandi_, Feb 10 2011
%F A016215 a(n) = (1/18)-(9/14)*(3)^n+(100/63)*(10)^n. _Antonio Alberto Olivares_, May 12 2012
%p A016215 a:= n-> add((10^(n+1-j)-3^(n+1-j))/7, j=0..n): seq(a(n), n=0..20); # _Zerinvary Lajos_, Jan 15 2007
%t A016215 CoefficientList[Series[1/((1-x)(1-3x)(1-10x)),{x,0,30}],x] (* or *) LinearRecurrence[{14,-43,30},{1,14,153},30] (* _Harvey P. Dale_, Aug 17 2017 *)
%K A016215 nonn,easy
%O A016215 0,2
%A A016215 _N. J. A. Sloane_