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 A218132 #11 Jul 14 2015 10:40:37 %S A218132 0,0,504,19656,262080,1953000,10077480,40353264,134217216,387419760, %T A218132 999999000,2357946360,5159778624,10604497176,20661044040,38443356000, %U A218132 68719472640,118587871584,198359284536,322687690920,511999992000,794280037320,1207269207144 %N A218132 Number of length 9 primitive (=aperiodic or period 9) n-ary words. %H A218132 Alois P. Heinz, <a href="/A218132/b218132.txt">Table of n, a(n) for n = 0..1000</a> %H A218132 <a href="/index/Rec#order_10">Index entries for linear recurrences with constant coefficients</a>, signature (10, -45, 120, -210, 252, -210, 120, -45, 10, -1). %F A218132 G.f.: 504*x^2*(x^6+29*x^5+175*x^4+310*x^3+175*x^2+29*x+1)/(x-1)^10. %F A218132 a(n) = n^9-n^3. %F A218132 a(0)=0, a(1)=0, a(2)=504, a(3)=19656, a(4)=262080, a(5)=1953000, a(6)=10077480, a(7)=40353264, a(8)=134217216, a(9)=387419760, a(n)=10*a(n-1)- 45*a(n-2)+120*a(n-3)-210*a(n-4)+252*a(n-5)- 210*a(n-6)+ 120*a(n-7)-45*a(n-8)+10*a(n-9)-a(n-10). - _Harvey P. Dale_, Feb 11 2015 %p A218132 a:= n-> (n^6-1)*n^3: %p A218132 seq(a(n), n=0..30); %t A218132 Table[n^9-n^3,{n,0,40}] (* or *) LinearRecurrence[{10,-45,120,-210,252,-210,120,-45,10,-1},{0,0,504,19656,262080,1953000,10077480,40353264,134217216,387419760},40] (* _Harvey P. Dale_, Feb 11 2015 *) %Y A218132 Row n=9 of A143324. %K A218132 nonn,easy %O A218132 0,3 %A A218132 _Alois P. Heinz_, Oct 21 2012