Dissecting a Heptagon
A convex heptagon has 14 diagonals. How many sets of diagonals (including the empty set) have the property that no two diagonals in the set cross at a point interior to the heptagon? Diagonals that share an endpoint do not count as crossing. Give an integer.
Related problems & prerequisites
Worth solving first
- Chords Without Crossing 4.0/10
- Ten Lines 4.0/10
- Paths Below the Diagonal 3.0/10
Source: The count of dissections by number of diagonals is the Kirkman-Cayley formula; the totals are the little Schröder numbers. Statement written for AxiomIQ.