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A011933 a(n) = floor( n*(n-1)*(n-2)*(n-3)/23 ).

%I A011933 #27 Nov 03 2024 09:34:05
%S A011933 0,0,0,0,1,5,15,36,73,131,219,344,516,746,1044,1424,1899,2483,3193,
%T A011933 4044,5055,6245,7633,9240,11088,13200,15600,18313,21365,24783,28596,
%U A011933 32833,37523,42699,48392,54636,61466,68916,77024,85827,95363,105673,116796,128775,141653,155473,170280,186120,203040,221088
%N A011933 a(n) = floor( n*(n-1)*(n-2)*(n-3)/23 ).
%H A011933 G. C. Greubel, <a href="/A011933/b011933.txt">Table of n, a(n) for n = 0..2500</a>
%H A011933 <a href="/index/Rec#order_27">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,-4,6,-4,1).
%F A011933 From _Chai Wah Wu_, Aug 02 2020: (Start)
%F A011933 a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) + a(n-23) - 4*a(n-24) + 6*a(n-25) - 4*a(n-26) + a(n-27) for n > 26.
%F A011933 G.f.: x^4*(1+x^2)*(1 + x + x^3 - x^5 + 4*x^6 - x^7 - x^8 + 2*x^9 + 2*x^11 - x^12 - x^13 + 4*x^14 - x^15 + x^17 + x^19 + x^20)/((1-x)^4*(1-x^23)). (End)
%t A011933 Table[Floor[(n(n-1)(n-2)(n-3))/23],{n,0,60}] (* _Harvey P. Dale_, Jun 22 2011 *)
%o A011933 (PARI) a(n) = n*(n-1)*(n-2)*(n-3)\23; \\ _Michel Marcus_, Jun 14 2017
%o A011933 (Magma) [Floor(24*Binomial(n,4)/23): n in [0..80]]; // _G. C. Greubel_, Nov 03 2024
%o A011933 (SageMath) [24*binomial(n,4)//23 for n in range(81)] # _G. C. Greubel_, Nov 03 2024
%Y A011933 Cf. A000332, A011915, A052762.
%K A011933 easy,nonn
%O A011933 0,6
%A A011933 _N. J. A. Sloane_
%E A011933 More terms added by _G. C. Greubel_, Nov 03 2024