A155745 a(n) = number of distinct (n+1)- nonnegative integer vectors describing, up to symmetry, the hyperplanes of the real n-dimensional cube.

1, 1, 2, 3, 7, 21, 143

Offset: 1

Author

Ilda P. F. da Silva (isilva(AT)cii.fc.ul.pt), Jan 26 2009

Keywords

• hard
• nonn

Comments

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.

Examples

			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.
		

References

• Ilda P. F. da Silva, Recursivity and geometry of the hypercube, Linear Algebra and its Apllications, 397(2005),223-233

Crossrefs

Cf. A007847