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A128989
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a(n) = (n^3 - n^2)*6^n.
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1
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0, 144, 3888, 62208, 777600, 8398080, 82301184, 752467968, 6530347008, 54419558400, 438984437760, 3448023220224, 26487087464448, 199671890116608, 1481082701414400, 10833062044631040, 78268873272459264
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OFFSET
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1,2
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LINKS
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FORMULA
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MATHEMATICA
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CoefficientList[Series[144 x (1 + 3 x)/(1 - 6 x)^4, {x, 0, 30}], x] (* Vincenzo Librandi, Feb 12 2013 *)
Table[(n^3-n^2)6^n, {n, 20}] (* or *) LinearRecurrence[{24, -216, 864, -1296}, {0, 144, 3888, 62208}, 20] (* Harvey P. Dale, Apr 29 2019 *)
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PROG
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(Magma) [(n^3-n^2)*6^n: n in [1..25]]; /* or */ I:=[0, 144, 3888, 62208]; [n le 4 select I[n] else 24*Self(n-1)-216*Self(n-2)+864*Self(n-3)-1296*Self(n-4): n in [1..25]]; // Vincenzo Librandi, Feb 12 2013
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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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