a)–c) Mean density of secondaries around primaries depending on their separation r. It should be noted that the r_i do not indicate annular bins. Σ(r_i) represents the number of secondaries within a circle of radius r_i (Sect. 3.2). Black dots indicate the values for the MA08 set, the open circles and error bars (in red) show the mean and standard deviation of 1000 pseudo-clusters – a) whole sample, b) early-type primaries only, c) late-type primaries only. d)–f) Cumulative distribution of primary-secondary separations r for the MA08 data (black) and 1000 pseudo-clusters (dashed, red) – d) whole sample, e) early-type primaries only, f) late-type primaries only. g) The same as a) but restricted to galaxies with velocity difference smaller than 250 km s^-1.