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Search: id:A155745
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| A155745 |
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a(n) = number of distinct (n+1)- nonnegative integer vectors describing, up to symmetry, the hyperplanes of the real n-dimensional cube. |
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1
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OFFSET
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1,3
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COMMENT
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Related to the sequence a'(n): 1,1,2,3,7,21,131. The sequence a'(n) has a recursive definition.
The following holds: a(n)>a'(n) for n>6.
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REFERENCES
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Ilda P. F. da Silva, Recursivity and geometry of the hypercube, Linear Algebra and its Apllications, 397(2005),223-233
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EXAMPLE
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For n=3 a(3)=2 because the 2 vectors (0,0,1,1) and (1,1,1,1) describe all the real planes spanned by the points of {-1,1}^3.
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CROSSREFS
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Cf. A007847
Sequence in context: A047693 A001532 A109456 this_sequence A067738 A053966 A010738
Adjacent sequences: A155742 A155743 A155744 this_sequence A155746 A155747 A155748
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KEYWORD
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hard,nonn
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AUTHOR
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Ilda P. F. da Silva (isilva(AT)cii.fc.ul.pt), Jan 26 2009
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