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A128074
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a(n) = (n^3+n)*9^n.
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10
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0, 18, 810, 21870, 446148, 7676370, 117979902, 1674039150, 22384294920, 285916320882, 3521652245010, 42113381995278, 491427393476940, 5617523480607090, 63094193590782438, 697970937800860110
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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(1)=18, a(2)=810, a(3)=21870, a(4)=446148, a(n)=36*a(n-1)- 486*a(n-2)+ 2916*a(n-3)-6561*a(n-4). - Harvey P. Dale, Jun 16 2011
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MATHEMATICA
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Table[(n^3+n)9^n, {n, 20}] (* or *) LinearRecurrence[{36, -486, 2916, -6561}, {18, 810, 21870, 446148}, 20] (* Harvey P. Dale, Jun 16 2011 *)
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PROG
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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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