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A198643
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a(n) = 5*3^n-1.
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6
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4, 14, 44, 134, 404, 1214, 3644, 10934, 32804, 98414, 295244, 885734, 2657204, 7971614, 23914844, 71744534, 215233604, 645700814, 1937102444, 5811307334, 17433922004, 52301766014, 156905298044, 470715894134, 1412147682404, 4236443047214
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OFFSET
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0,1
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LINKS
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FORMULA
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a(n) = 3*a(n-1)+2 = 2*A060816(n+1).
G.f.: ( 4-2*x ) / ( (3*x-1)*(x-1) ). - R. J. Mathar, Nov 17 2011
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PROG
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(Magma) [5*3^n-1: n in [0..30]]
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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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