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A143107
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Let H(2,d) be the space of polynomials p(x,y) of two variables with nonnegative coefficients such that p(x,y) = 1 whenever x + y = 1; a(n) is the number of different polynomials in H(2,d) with exactly n distinct monomials and of maximum degree, i.e., of degree 2n-3.
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3
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0, 1, 1, 2, 4, 2, 4, 8, 4, 2, 24, 2
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OFFSET
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1,4
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COMMENTS
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It is unknown if this sequence is bounded. For all n >= 4, a(n) is at least two. It is unknown if it is 2 for infinitely many n. It is unknown if it is always even for all n >= 2. Note that 2n-3 appears in A143106 if and only if a(n) is 1 or 2.
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LINKS
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EXAMPLE
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a(3) = 1 as x^3 + 3xy + y^3 is the unique polynomial in H(2,d) with 3 terms and of maximum degree (in this case 3).
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MATHEMATICA
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See the paper by Lebl and Lichtblau.
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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One more term (24), added addendum to and corrected title of paper - Jiri Lebl, Feb 08 2013
Added another term (2) that was computed in the newer version of the addendum. Edited by Jiri Lebl, May 02 2014
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STATUS
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approved
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