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A024191
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[ (3rd elementary symmetric function of 3,4,...,n+4)/(3+4+...+n+4) ].
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3
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5, 19, 47, 95, 170, 280, 434, 642, 915, 1265, 1705, 2249, 2912, 3710, 4660, 5780, 7089, 8607, 10355, 12355, 14630, 17204, 20102, 23350, 26975, 31005, 35469, 40397, 45820, 51770, 58280, 65384, 73117, 81515, 90615, 100455, 111074, 122512, 134810, 148010
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OFFSET
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1,1
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LINKS
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FORMULA
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G.f.: x*(5-6*x+2*x^2)/(1-x)^5.
a(1)=5, a(2)=19, a(3)=47, a(4)=95, a(5)=170, a(n)=5*a(n-1)- 10*a(n-2)+ 10*a(n-3)-5*a(n-4)+a(n-5). - Harvey P. Dale, Apr 28 2014
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MATHEMATICA
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Table[n(n+1)(n^2+13n+46)/24, {n, 40}] (* or *) LinearRecurrence[ {5, -10, 10, -5, 1}, {5, 19, 47, 95, 170}, 40] (* Harvey P. Dale, Apr 28 2014 *)
CoefficientList[Series[(5 - 6 x + 2 x^2)/(1 - x)^5, {x, 0, 40}], x] (* Vincenzo Librandi, Apr 28 2014 *)
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PROG
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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