A planar graph is a network that can be drawn in a plane without any edges intersecting.

A graph is planar if it can be drawn in a plane without graph edges crossing (i.e., it has graph crossing number 0). The number of planar graphs with n = 1, 2, ... nodes are 1, 2, 4, 11, 33, 142, 822, 6966, 79853, ... (OEIS A005470; Wilson 1975, p. 162), the first few of which are illustrated above. The corresponding numbers of planar connected graphs are 1, 1, 1, 2, 6, 20, 99, 646, 5974, 71885, ... (OEIS A003094; Steinbach 1990, p.

apex graph | Barnette's conjecture | biplanar graph | complete graph | critical nonplanar graph | doublecross graph | double-toroidal graph | dual graph | Fáry theorem | graph crossing number | graph genus | graph skewness | graph thickness | integral embedding | Kuratowski's theorem | nonplanar graph | outerplanar graph | planar connected graph | planar embedding | planar straight line embedding | polyhedral graph | rectilinear crossing number | singlecross graph | Steinitz's theorem | toroidal graph | triangulated graph | utility graph

college level