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 A011915 #32 Dec 30 2024 04:00:15
%S A011915 0,0,0,0,4,24,72,168,336,604,1008,1584,2376,3432,4804,6552,8736,11424,
%T A011915 14688,18604,23256,28728,35112,42504,51004,60720,71760,84240,98280,
%U A011915 114004,131544,151032,172608,196416,222604,251328,282744,317016,354312
%N A011915 a(n) = floor(n*(n-1)*(n-2)*(n-3)/5).
%H A011915 Vincenzo Librandi, <a href="/A011915/b011915.txt">Table of n, a(n) for n = 0..1000</a>
%H A011915 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1,1,-4,6,-4,1).
%F A011915 a(n) = +4*a(n-1) -6*a(n-2) +4*a(n-3) -a(n-4) +a(n-5) -4*a(n-6) +6*a(n-7) -4*a(n-8) +a(n-9).
%F A011915 G.f.: 4*x^4*(1+2*x+2*x^3+x^4) / ( (1-x)^5*(1+x+x^2+x^3+x^4) ). - _R. J. Mathar_, Apr 15 2010
%F A011915 a(n) = 4*A011930(n). - _G. C. Greubel_, Oct 20 2024
%t A011915 Table[Floor[n(n-1)(n-2)(n-3)/5], {n,60}] (* _Stefan Steinerberger_, Apr 10 2006 *)
%t A011915 CoefficientList[Series[4*x^4*(1+2*x+2*x^3+x^4)/((1-x)^4*(1+x^5)),{x,0,60}],x] (* _Vincenzo Librandi_, Jun 19 2012 *)
%o A011915 (Magma) [Floor(n*(n-1)*(n-2)*(n-3)/5): n in [0..60]]; // _Vincenzo Librandi_, Jun 19 2012
%o A011915 (SageMath) [24*binomial(n,4)//5 for n in range(61)] # _G. C. Greubel_, Oct 20 2024
%Y A011915 Sequences of the form floor(24*binomial(n,4)/m): A052762 (m=1), A033486 (m=2), A162668 (m=3), A033487 (m=4), this sequence (m=5), A033488 (m=6), A011917 (m=7), A050534 (m=8), A011919 (m=9), 2*A011930 (m=10), A011921 (m=11), A034827 (m=12), A011923 (m=13), A011924 (m=14), A011925 (m=15), A011926 (m=16), A011927 (m=17), A011928 (m=18), A011929 (m=19), A011930 (m=20), A011931 (m=21), A011932 (m=22), A011933 (m=23), A000332 (m=24), A011935 (m=25),A011936 (m=26), A011937 (m=27), A011938 (m=28), A011939 (m=29), A011940 (m=30), A011941 (m=31), A011942 (m=32), A011795 (m=120).
%K A011915 nonn,easy
%O A011915 0,5
%A A011915 _N. J. A. Sloane_
%E A011915 More terms from _Stefan Steinerberger_, Apr 10 2006
%E A011915 Zero added in front by _R. J. Mathar_, Apr 15 2010