login
a(n) = number of distinct (n+1)- nonnegative integer vectors describing, up to symmetry, the hyperplanes of the real n-dimensional cube.
0

%I #1 Feb 27 2009 03:00:00

%S 1,1,2,3,7,21,143

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

%C Related to the sequence a'(n): 1,1,2,3,7,21,131. The sequence a'(n) has a recursive definition.

%C The following holds: a(n)>a'(n) for n>6.

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

%e 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.

%Y Cf. A007847

%K hard,nonn

%O 1,3

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