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A027470
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a(n) = 225*(n-1)*(n-2)/2.
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1
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225, 675, 1350, 2250, 3375, 4725, 6300, 8100, 10125, 12375, 14850, 17550, 20475, 23625, 27000, 30600, 34425, 38475, 42750, 47250, 51975, 56925, 62100, 67500, 73125, 78975, 85050, 91350, 97875, 104625, 111600, 118800, 126225
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OFFSET
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3,1
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LINKS
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FORMULA
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Numerators of sequence a[n,n-2] in (a[i,j])^4 where a[i,j] = binomial(i-1, j-1)/2^(i-1) if j<=i, 0 if j>i.
a(3)=225, a(4)=675, a(5)=1350, a(n) = 3*a(n-1) -3*a(n-2) +a(n-3). - Harvey P. Dale, Feb 01 2013
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MAPLE
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MATHEMATICA
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LinearRecurrence[{3, -3, 1}, {225, 675, 1350}, 40] (* Harvey P. Dale, Feb 01 2013 *)
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PROG
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(Sage) [225*binomial(n-1, 2) for n in (3..50)] # G. C. Greubel, May 14 2021
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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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