A configuration in the plane is denoted by (pγ ℓπ), where p is the number of points, ℓ the number of lines, γ the number of lines per point, and π the number of points per line. These numbers necessarily satisfy the equation See more

The number of nonisomorphic configurations of type (n3), starting at n = 7, is given by the sequence
1, 1, 3, 10, 31, 229, 2036, 21399, 245342, ... (sequence A001403 in the OEIS)
These numbers count configurations as abstract incidence … See more

Higher dimensions
The concept of a configuration may be generalized to higher dimensions, for instance to points … See more

Notable projective configurations include the following:
• (11), the simplest possible configuration, consisting of a point … See more

The projective dual of a configuration (pγ ℓπ) is a (ℓπ pγ) configuration in which the roles of "point" and "line" are exchanged. Types of configurations therefore come in dual pairs, except … See more

There are several techniques for constructing configurations, generally starting from known configurations. Some of the simplest of … See more

• Perles configuration, a set of 9 points and 9 lines which do not all have equal numbers of incidences to each other See more