Search Results for ""

The problem of deciding if four colors are sufficient to color any map on a plane or sphere.

A symmetric block design (4n+3, 2n+1, n) which is equivalent to a Hadamard matrix of order 4n+4. It is conjectured that Hadamard designs exist for all integers n>0, but this ...

Every graph with n vertices and maximum vertex degree Delta(G)<=k is (k+1)-colorable with all color classes of size |_n/(k+1)_| or [n/(k+1)], where |_x_| is the floor ...

The Hajós number h(G) of a graph G is the maximum k such that G contains a subdivision of the complete graph K_k.

A binary Hamming code H_r of length n=2^r-1 (with r>=2) is a linear code with parity-check matrix H whose columns consist of all nonzero binary vectors of length r, each used ...

The Hamming distance between two vertices of a hypercube is the number of coordinates at which the two vertices differ.

One of the 24 7-polyiamonds.

A heptomino is a 7-polyomino. There are 108 free (illustrated above), 196 one-sided, and 760 fixed heptominoes. There is a single heptomino containing a hole (illustrated ...

The Herschel is the heptomino illustrated above which is shaped like the astronomical symbol for Saturn. It was misnamed by early investigators of the game of life who ...

The 6-polyiamond illustrated above.