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A087452
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G.f.: (2-x)/((1+3x)(1-4x)); e.g.f.: exp(4x) + exp(-3x); a(n) = 4^n + (-3)^n.
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1
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2, 1, 25, 37, 337, 781, 4825, 14197, 72097, 242461, 1107625, 4017157, 17308657, 65514541, 273218425, 1059392917, 4338014017, 17050729021, 69106897225, 273715645477, 1102998412177, 4387586157901, 17623567104025, 70274600998837, 281757406247137
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OFFSET
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0,1
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COMMENTS
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Generalized Lucas-Jacobsthal numbers.
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LINKS
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FORMULA
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a(n) = (-3)^n+4^n.
a(n) = a(n-1) + 12*a(n-2) for n > 1; a(0)=2, a(1)=1. - Philippe Deléham, Sep 19 2009
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MATHEMATICA
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LinearRecurrence[{1, 12}, {2, 1}, 30] (* Harvey P. Dale, Nov 06 2022 *)
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PROG
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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