%I #19 Oct 18 2024 06:29:57
%S 0,0,0,0,0,2,4,8,12,19,27,38,50,66,84,105,129,156,188,223,263,306,355,
%T 408,467,530,600,675,756,843,936,1037,1144,1259,1380,1510,1647,1793,
%U 1946,2109,2280,2460,2649,2847,3056,3274,3503,3741,3991,4251,4523,4805,5100,5406,5724,6054,6396,6752,7120
%N a(n) = floor( n*(n-1)*(n-2)/26 ).
%H G. C. Greubel, <a href="/A011908/b011908.txt">Table of n, a(n) for n = 0..2000</a>
%H <a href="/index/Rec#order_16">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1,0,0,0,0,0,0,0,0,0,1,-3,3,-1).
%F From _R. J. Mathar_, Apr 15 2010: (Start)
%F a(n) = +3*a(n-1) -3*a(n-2) +a(n-3) +a(n-13) -3*a(n-14) +3*a(n-15) -a(n-16).
%F G.f.: x^5*(2-2*x+2*x^2-2*x^3+3*x^4-2*x^5+2*x^6-2*x^7+3*x^8-2*x^9+x^10) / ( (1-x)^3*(1-x^13) ). (End)
%t Floor[3*Binomial[Range[0, 75], 3]/13] (* _G. C. Greubel_, Oct 18 2024 *)
%o (Magma) [Floor(3*Binomial(n,3)/13): n in [0..75]]; // _G. C. Greubel_, Oct 18 2024
%o (SageMath) [3*binomial(n,3)//13 for n in range(76)] # _G. C. Greubel_, Oct 18 2024
%Y Cf. A011886.
%K nonn
%O 0,6
%A _N. J. A. Sloane_
%E More terms added by _G. C. Greubel_, Oct 18 2024