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%I #16 Mar 20 2024 13:55:02
%S 0,60,690,3630,13035,37059,89839,193879,382834,704694,1225368,2032668,
%T 3240693,4994613,7475853,10907677,15561172,21761632,29895342,40416762,
%U 53856111,70827351,92036571,118290771,150507046,189722170,237102580
%N a(n) =60*sum(1<=u<=v<=w<=m,u^2*v^2/w).
%C Always an integer. Can be expressed as a polynomial with rational coefficients of degree 6.
%H <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (7,-21,35,-35,21,-7,1).
%F n*(200*n^5+1752*n^4+5705*n^3+8370*n^2+5075*n+498)/360. - _Vladeta Jovovic_, Oct 27 2003
%F G.f.: -x*(x^5-6*x^4+15*x^3+60*x^2+270*x+60) / (x-1)^7. - _Colin Barker_, Jun 19 2013
%t LinearRecurrence[{7,-21,35,-35,21,-7,1},{0,60,690,3630,13035,37059,89839},30] (* _Harvey P. Dale_, Mar 20 2024 *)
%Y Cf. A088941, A088942, A088943, A088944.
%K nonn,easy
%O 0,2
%A _Benoit Cloitre_, Oct 25 2003
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