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A089929
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Algebraic degree of cot(Pi/n).
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1
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1, 2, 1, 4, 2, 6, 2, 6, 4, 10, 2, 12, 6, 8, 4, 16, 6, 18, 4, 12, 10, 22, 4, 20, 12, 18, 6, 28, 8, 30, 8, 20, 16, 24, 6, 36, 18, 24, 8, 40, 12, 42, 10, 24, 22, 46, 8, 42, 20, 32, 12, 52, 18, 40, 12, 36, 28, 58, 8, 60, 30, 36, 16, 48, 20, 66, 16, 44, 24, 70, 12
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OFFSET
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2,2
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COMMENTS
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Also the algebraic degrees of the surface area and volume of an n-prism with unit edge lengths.
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LINKS
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Eric Weisstein's World of Mathematics, Prism
Eric Weisstein's World of Mathematics, Cotangent
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FORMULA
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MATHEMATICA
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a[n_] := Exponent[ MinimalPolynomial[ Cot[Pi/n]][x], x]; Table[ a[n], {n, 2, 52}] (* Jean-François Alcover, Oct 03 2012 *)
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CROSSREFS
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KEYWORD
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nonn,hard,nice
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AUTHOR
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EXTENSIONS
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a(47) corrected and more terms added by Jon Maiga, Sep 01 2019
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STATUS
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approved
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