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A143107 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. +0
4
0, 1, 1, 2, 4, 2, 4, 8, 4, 2 (list; graph; listen)
OFFSET

1,4

COMMENT

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 one or 2.

REFERENCES

J. P. D'Angelo and J. Lebl. Complexity results for CR mappings between spheres. to appear in Internat. J. Math., preprint arXiv:0708.3232.

J. P. D'Angelo, Simon Kos and Emily Riehl. A sharp bound for the degree of proper monomial mappings between balls. J. Geom. Anal., 13(4):581-593, 2003.

J. Lebl and D. Lichtblau. Uniqueness of certain polynomials constant on a hyperplane. preprint

LINKS

J. P. D'Angelo and J. Lebl. Complexity results for CR mappings between spheres, to appear in Internat. J. Math.

EXAMPLE

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)

MATHEMATICA

See the paper by Lebl-Lichtblau

CROSSREFS

Cf. A143106, A143108, A143109.

Sequence in context: A128859 A047975 A112791 this_sequence A166242 A051638 A155682

Adjacent sequences: A143104 A143105 A143106 this_sequence A143108 A143109 A143110

KEYWORD

nonn,more

AUTHOR

Jiri Lebl (jlebl(AT)math.uiuc.edu), Jul 25 2008

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Last modified December 2 11:54 EST 2009. Contains 167921 sequences.


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