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A120655
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Expansion of (1-x)*(1+8*x+60*x^2)/((1-2*x)*(1+2*x)*(1-4*x)).
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2
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1, 11, 100, 368, 1696, 6656, 27520, 109568, 441856, 1765376, 7075840, 28295168, 113238016, 452919296, 1811906560, 7247495168, 28990898176, 115963068416, 463855943680, 1855421677568, 7421701390336, 29686797172736
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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(n) = 3*(-2)^n - 5*2^n + 27*4^(n-1) for n>0.
a(n) = 4*a(n-1) + 4*a(n-2) - 16*a(n-3) for n>3.
G.f.: (1-x)*(1+8*x+60*x^2)/((1-2*x)*(1+2*x)*(1-4*x)). (End)
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MATHEMATICA
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LinearRecurrence[{4, 4, -16}, {1, 11, 100, 368}, 50] (* G. C. Greubel, Dec 20 2022 *)
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PROG
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(Magma) [1] cat [3*(-2)^n - 5*2^n + 27*4^(n-1): n in [1..40]]; // G. C. Greubel, Dec 20 2022
(SageMath) [3*(-2)^n - 5*2^n + 27*4^(n-1) - (15/4)*int(n==0) for n in range(41)] # G. C. Greubel, Dec 20 2022
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CROSSREFS
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KEYWORD
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nonn,easy,less
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AUTHOR
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EXTENSIONS
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Meaningful name using g.f. from Joerg Arndt, Dec 26 2022
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STATUS
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approved
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