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A016304
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Expansion of 1/((1-2*x)*(1-6*x)*(1-7*x)).
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3
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1, 15, 157, 1419, 11869, 94731, 733069, 5551323, 41378557, 304766187, 2224062061, 16112628987, 116053574365, 831966057483, 5941308640333, 42294437942811, 300292730428093, 2127439102098219, 15044413649559085
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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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From Vincenzo Librandi_, Aug 25 2011: (Start)
a(0)=1, a(1)=15, a(2)=157, a(n) = 15*a(n-1) - 68*a(n-2) + 84*a(n-3);
a(0)=1, a(1)=15, a(n) = 13*a(n-1) - 42*a(n-2) + 2^n. (End)
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MATHEMATICA
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CoefficientList[Series[1/((1-2x)(1-6x)(1-7x)), {x, 0, 30}], x] (* or *) LinearRecurrence[{15, -68, 84}, {1, 15, 157}, 30]
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PROG
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(Sage) [(7^n - 2^n)/5-(6^n - 2^n)/4 for n in range(2, 21)] # Zerinvary Lajos, Jun 05 2009
(Magma) [ n eq 1 select 1 else n eq 2 select 15 else n eq 3 select 157 else 15*Self(n-1)-68*Self(n-2) +84*Self(n-3): n in [1..20] ]; // Vincenzo Librandi, Aug 25 2011
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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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