Perfect Rectangle

A Rectangle which cannot be built up of Squares all of different sizes is called an imperfectrectangle. A Rectangle which can be built up of Squares all of different sizes is called perfect. The number of perfect rectangles of orders 8, 9, 10, ... are 0, 2, 6, 22, 67, 213, 744, 2609, ... (Sloane's A002839) andthe corresponding numbers of imperfect rectangles are 0, 1, 0, 0, 9, 34, 103, 283, ... (Sloane's A002882).

References

Sloane, N. J. A. Sequences A002839/M1658 and A002882/M4614 in ``An On-Line Version of the Encyclopedia of Integer Sequences.''http://www.research.att.com/~njas/sequences/eisonline.html.

• Nim-Sum
• Nim-Value
• n-in-a-Row
• Nine-Point Center
• Nine-Point Circle
• Nine-Point Conic
• Nint
• Nint Zeta Function
• Nirenberg's Conjecture
• Niven Number
• Niven's Constant
• n-minex
• Nobbs Points
• Noble Number
• Node (Algebraic Curve)
• Node (Fixed Point)
• Node (Graph)
• Noetherian Module
• Noetherian Ring
• Noether-Lasker Theorem
• Noether's Fundamental Theorem
• Noether's Transformation Theorem
• Noise
• Noise Sphere
• Nolid