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 A218130 #9 Oct 13 2017 16:34:23
%S A218130 0,0,54,696,4020,15480,46410,117264,261576,530640,998910,1770120,
%T A218130 2984124,4824456,7526610,11387040,16772880,24132384,34006086,47038680,
%U A218130 63991620,85756440,113368794,148023216,191088600,244124400,308897550,387400104,481867596,594798120
%N A218130 Number of length 6 primitive (=aperiodic or period 6) n-ary words.
%H A218130 Alois P. Heinz, <a href="/A218130/b218130.txt">Table of n, a(n) for n = 0..1000</a>
%H A218130 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (7, -21, 35, -35, 21, -7, 1).
%F A218130 G.f.: -6*x^2*(9+53*x+47*x^2+11*x^3)/(x-1)^7.
%F A218130 a(n) = n^6-n^3-n^2+n.
%p A218130 a:= n-> (((n^3-1)*n-1)*n+1)*n:
%p A218130 seq(a(n), n=0..30);
%t A218130 Table[n^6-n^3-n^2+n,{n,0,30}] (* or *) LinearRecurrence[{7,-21,35,-35,21,-7,1},{0,0,54,696,4020,15480,46410},30] (* _Harvey P. Dale_, Oct 13 2017 *)
%Y A218130 Row n=6 of A143324.
%K A218130 nonn,easy
%O A218130 0,3
%A A218130 _Alois P. Heinz_, Oct 21 2012