| Property: | Mathematical Set: |
|---|
| Any number which is the sum of the previous two numbers in the series beginning: 2,1... | |
| Any real number which cannot be expressed as a ratio of two integers. | |
| The product of n(n-1)(n-2)(n-3)...(n-(n-1)), where n is any positive integer. | |
| Any positive integer equal to the sum of its positive divisors excluding the number itself. | |
| The product of any integer n, raised to the power of 2. | |
| Any real number less than 0. | |
| Any number which is equal to n+(n-1)+(n-2)+...+(n-(n-1)), where n is any positive integer. | |
| Any positive integer that is divisible only by 1 and itself. | |
| Any integer which is not evenly divisible by 2. | |
| Any number which has two constituent parts - a real part and an imaginary part. | |
| Any positive integer (although some people also include 0 as an element of this set). | |
| Any positive real number expressed as a fraction of 100. | |
| Any number which is the sum of the previous two numbers in the series beginning: 0,1... | |
Periodic Table
Planets from the Sun
Digits of Pi
