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A275876
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a(n) = 4*n*(n^2 - 3*n - 1)/3.
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1
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0, -4, -8, -4, 16, 60, 136, 252, 416, 636, 920, 1276, 1712, 2236, 2856, 3580, 4416, 5372, 6456, 7676, 9040, 10556, 12232, 14076, 16096, 18300, 20696, 23292, 26096, 29116, 32360, 35836, 39552, 43516, 47736, 52220, 56976, 62012, 67336, 72956, 78880, 85116, 91672, 98556, 105776, 113340, 121256
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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) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n>3.
G.f.: -4*x*(1-2*x-x^2) / (1-x)^4. (End)
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MATHEMATICA
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LinearRecurrence[{4, -6, 4, -1}, {0, -4, -8, -4}, 50] (* G. C. Greubel, Apr 28 2019 *)
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PROG
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(PARI) concat(0, Vec(-4*x*(1-2*x-x^2)/(1-x)^4 + O(x^50))) \\ Colin Barker, Aug 15 2016
(Magma) [4*n*(n^2-3*n-1)/3: n in [0..50]]; // G. C. Greubel, Apr 28 2019
(Sage) [4*n*(n^2-3*n-1)/3 for n in (0..50)] # G. C. Greubel, Apr 28 2019
(GAP) List([0..50], n-> 4*n*(n^2-3*n-1)/3) # G. C. Greubel, Apr 28 2019
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CROSSREFS
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KEYWORD
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sign,easy
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AUTHOR
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STATUS
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approved
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