Orchard Visibility Problem
A tree is planted at each Lattice Point in a circular orchard which has Center at the Origin andRadius 
. If the radius of trees exceeds 
units, one is unable to see out of the orchard in any direction. However, if the Radii of the trees are 
, one can see out at certainAngles.
References
Honsberger, R. ``The Orchard Problem.'' Ch. 4 in Mathematical Gems I. Washington, DC: Math. Assoc. Amer., pp. 43-52, 1973.
- Hardy's Inequality
- Hardy's Rule
- Harmonic Addition Theorem
- Harmonic Analysis
- Harmonic Brick
- Harmonic Conjugate Function
- Harmonic Conjugate Points
- Harmonic Coordinates
- Harmonic Decomposition
- Harmonic Divisor Number
- Harmonic Equation
- Harmonic Function
- Harmonic-Geometric Mean
- Harmonic Homology
- Harmonic Logarithm
- Harmonic Map
- Harmonic Mean
- Harmonic Mean Index
- Harmonic Number
- Harmonic Progression
- Harmonic Range
- Harmonic Ratio
- Harmonic Segment
- Harmonic Series
- Harmonic System of Points