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A291288
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a(n) = binomial(n+3, 3)*(1 + binomial(n+2, 3)/4).
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3
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1, 5, 20, 70, 210, 546, 1260, 2640, 5115, 9295, 16016, 26390, 41860, 64260, 95880, 139536, 198645, 277305, 380380, 513590, 683606, 898150, 1166100, 1497600, 1904175, 2398851, 2996280, 3712870, 4566920, 5578760, 6770896, 8168160, 9797865, 11689965
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OFFSET
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0,2
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LINKS
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FORMULA
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a(n) = (n+1)*(n+2)*(n+3)*(n+4)*(n^2-n+6)/144.
n*a(n) - (2+3*n)*a(n-1) + (8*n-16)*a(n-2) - (12+6*n)*a(n-3) = 0.
G.f.: (6*x^2-2*x+1)/(1-x)^7. (End)
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MAPLE
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f:=n->binomial(n+3, 3)*(1+binomial(n+2, 3)/4);
[seq(f(n), n=0..40)];
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MATHEMATICA
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Table[Binomial[n+3, 3](1+Binomial[n+2, 3]/4), {n, 0, 40}] (* or *) LinearRecurrence[{7, -21, 35, -35, 21, -7, 1}, {1, 5, 20, 70, 210, 546, 1260}, 40] (* Harvey P. Dale, Mar 12 2024 *)
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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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