## polygonal numberThe number of equally spaced dots needed to draw a polygon. Polygonal numbers, which are a type of figurate number, include square numbers, triangular numbers, pentagonal numbers, and hexagonal numbers. Polygonal numbers form an arithmetic sequence of the second order. The general term of these sequences is where d is one of the numbers 1, 2, 3, ...With d = 1 we obtain the triangular
numbers: 1, 3, 6, 10, 15, ... With d = 2 we obtain the square
numbers: 1, 4, 9, 16, 25, ... With d = 3 we obtain the pentagonal numbers: 1,
5, 12, 22, 35, ... ## Related category• TYPES OF NUMBERS | |||||

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