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A062990
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Eighth column (r=7) of FS(5) staircase array A062985.
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2
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5, 30, 110, 315, 771, 1688, 3396, 6390, 11385, 19382, 31746, 50297, 77415, 116160, 170408, 245004, 345933, 480510, 657590, 887799, 1183787, 1560504, 2035500, 2629250, 3365505, 4271670, 5379210, 6724085, 8347215
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OFFSET
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0,1
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COMMENTS
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In the Frey-Sellers reference this sequence is called {(n+2) over 7}_{4}, n >= 0.
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LINKS
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FORMULA
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a(n) = A062985(n+2, 7) = (n+1)*(n+2)*(n+3)*(n^4 + 29*n^3 + 326*n^2 + 1744*n + 4200)/7!.
G.f.: N(5;1, x)/(1-x)^8 with N(5;1, x)= 5-10*x+10*x^2-5*x^3+x^4 = (1-(1-x)^5)/x polynomial of second row of A062986.
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MAPLE
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[seq((binomial(n+7, n)-binomial(n+2, n)), n=1..29)]; # Zerinvary Lajos, Jun 23 2006
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MATHEMATICA
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Table[Binomial[n+7, n]-Binomial[n+2, n], {n, 30}] (* or *) LinearRecurrence[ {8, -28, 56, -70, 56, -28, 8, -1}, {5, 30, 110, 315, 771, 1688, 3396, 6390}, 30] (* Harvey P. Dale, Jun 09 2016 *)
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PROG
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(PARI) { for (n=0, 1000, m=n + 1; a=binomial(m + 7, m) - binomial(m + 2, m); write("b062990.txt", n, " ", a) ) } \\ Harry J. Smith, Aug 15 2009
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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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EXTENSIONS
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STATUS
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approved
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