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 A011917 #15 Jul 08 2025 02:42:25
%S A011917 0,0,0,0,3,17,51,120,240,432,720,1131,1697,2451,3432,4680,6240,8160,
%T A011917 10491,13289,16611,20520,25080,30360,36432,43371,51257,60171,70200,
%U A011917 81432,93960,107880,123291,140297,159003
%N A011917 [ n(n-1)(n-2)(n-3)/7 ].
%H A011917 Harvey P. Dale, <a href="/A011917/b011917.txt">Table of n, a(n) for n = 0..1000</a>
%H A011917 <a href="/index/Rec#order_11">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1,0,0,1,-4,6,-4,1).
%F A011917 a(n) = +4*a(n-1) -6*a(n-2) +4*a(n-3) -a(n-4) +a(n-7) -4*a(n-8) +6*a(n-9) -4*a(n-10) +a(n-11). G.f.: x^4*(3+5*x+x^2+6*x^3+x^4+5*x^5+3*x^6) / ( (1-x)^5*(1+x+x^2+x^3+x^4+x^5+x^6) ). - _R. J. Mathar_, Apr 15 2010
%t A011917 Table[Floor[Times@@(n-Range[0,3])/7],{n,0,40}] (* or *) LinearRecurrence[ {4,-6,4,-1,0,0,1,-4,6,-4,1},{0,0,0,0,3,17,51,120,240,432,720},50] (* _Harvey P. Dale_, Oct 20 2016 *)
%o A011917 (PARI) a(n)=n*(n-1)*(n-2)*(n-3)\7 \\ _Charles R Greathouse IV_, Oct 18 2022
%K A011917 nonn,easy
%O A011917 0,5
%A A011917 _N. J. A. Sloane_