Examples from the Web for heptagonal
Meshes subregular pentagonal (intermingled with single tetragonal, hexagonal, and heptagonal meshes).
The effect of a heptagonal stem on an octagonal base or plinth is certainly odd.Bell's Cathedrals: The Abbey Church of Tewkesbury|H. J. L. J. Mass
Meshes regular or subregular, hexagonal, often intermingled with a variable number of pentagonal and heptagonal meshes.