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A259457
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From higher-order arithmetic progressions.
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1
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3, 66, 1050, 15300, 220500, 3245760, 49533120, 789264000, 13172544000, 230519520000, 4229703878400, 81315551116800, 1636227552960000, 34417989365760000, 755835784704000000, 17305616126582784000, 412559358036553728000, 10227311816872550400000
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OFFSET
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0,1
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LINKS
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FORMULA
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Conjecture: 3*n*a(n) +(-3*n^2-19*n-44)*a(n-1) -2*(n+2)^2*a(n-2)=0. - R. J. Mathar, Jul 15 2015
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MAPLE
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rX := proc(n, a, d)
n*a+(n-1)*n/2*d;
end proc:
mul(rX(i, a, d), i=1..n+2) ;
coeftayl(%, d=0, 2) ;
coeftayl(%, a=0, n) ;
end proc:
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MATHEMATICA
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rX[n_, a_, d_] := n*a + (n-1)*n/2*d;
Product[rX[i, a, d], {i, 1, n+3}]//
SeriesCoefficient[#, {d, 0, 2}]&//
SeriesCoefficient[#, {a, 0, n+1}]&;
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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