A set includes seats, each seat includes a chair and a lateral pedestal arranged laterally on one side of the chair. The chairs and the lateral pedestals are arranged in a staggered configuration in two parallel rows. Each seat has a covering shell determining a rear surface in a rear zone of the chair and determining a front surface in a front zone of the lateral pedestal. A space between a rear surface of a front seat and a front surface of a rear seat forms a passage for an occupant of the rear seat. In a vertical cross section the rear surface and the front surface have convex profiles facing one another, a width of the passage increasing in the direction of decreasing heights from a height of minimum width, and increasing in the direction of increasing heights from the height of minimum width.