Examples for

# Special Numbers

Many numbers are generated from or represented by symbolic, geometric or otherwise interesting patterns and criteria. These live under the umbrella term "special numbers." Wolfram|Alpha is prepared for queries about different kinds of such numbers, such as polygonal numbers, perfect numbers, Lucas numbers, numbers from Pascal's triangle and more.

Query polygonal numbers and do calculations with them or check whether values are members of a figurate number class.

#### Compute a polygonal number:

#### Determine whether a number belongs to a given class:

Find a number or a set of numbers meeting certain criteria or check whether an individual value meets specified criteria.

#### Find a number matching specified criteria:

#### Find numbers matching specified criteria:

Analyze numbers in terms of their relationship with the sum of their divisors.

#### Determine whether a number belongs to a given class:

Perform operations on defined sets of numbers.

#### Take the sum or product of a sequence of numbers of a given type:

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Query elements and rows of this famous triangle or analyze the values of its elements subject to a modulus or other condition.