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%I #12 Jun 17 2017 03:53:50
%S 0,60,390,1450,4045,9421,19361,36281,63326,104466,164592,249612,
%T 366547,523627,730387,997763,1338188,1765688,2295978,2946558,3736809,
%U 4688089,5823829,7169629,8753354,10605230,12757940,15246720,18109455,21386775
%N a(n)=60*sum(1<=i<=j<=k<=n,i^2*j/k).
%C Always an integer. Can be expressed as a polynomial with rational coefficients of degree 5.
%H <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (6,-15,20,-15,6,-1).
%F a(n) = n/120 * (96n^4 + 765n^3 + 2210n^2 + 2275n + 1354).
%F G.f.: x*(x^4-5*x^3+10*x^2+30*x+60) / (x-1)^6. - _Colin Barker_, Jun 15 2013
%o (PARI) a(n)=60*sum(k=1,n,sum(j=1,k,sum(i=1,j,i^2*j/k)))
%Y Cf. A088941, A088943.
%K nonn,easy
%O 0,2
%A _Benoit Cloitre_, Oct 25 2003
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