The term figurate number is used by different writers for members of different sets of numbers, generalizing from triangular numbers to different shapes (polygonal numbers) and different dimensions (polyhedral numbers). The term can mean
- polygonal number
- a number represented as a discrete r-dimensional regular geometric pattern of r-dimensional balls such as a polygonal number (for r = 2) or a polyhedral number (for r = 3).
- a member of the subset of the sets above containing only triangular numbers, pyramidal numbers, and their analogs in other dimensions.
Read more about Figurate Number: Terminology, History, Triangular Numbers, Gnomon
Famous quotes containing the word number:
“How often should a woman be pregnant? Continually, or hardly ever? Or must there be a certain number of pregnancy anniversaries established by fashion? What do you, at the age of forty-three, have to say on the subject? Is it a fact that the laws of nature, or of the country, or of propriety, have ordained this time of life for sterility?”
—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)