It seems like all of us could use some extra luck these days. Lucky for us, there are some numbers out there that are considered good luck!
First, how can we figure out which numbers are lucky?
According to Wikipedia, "In number theory, a lucky number is a natural number in a set which is generated by a certain 'sieve." We must sift through numbers to find the lucky ones. And there are a few ways to approach the idea.
First we have "Lucky Number of Euler."
- A lucky number of Euler is a number p such that the prime-generating polynomial
- n^2-n+p
- The second is obtained by writing out all odd numbers: 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, .... The first odd number
is 3, so strike out every third number from the list: 1, 3, 7, 9, 13, 15, 19, .... The first odd number greater than 3 in the list is 7, so strike out every seventh number: 1, 3, 7, 9, 13, 15, 21, 25, 31, ....
Second, we have "Number of Lucky Primes."
- The "lucky numbers" can be constructed with this sieve. The red ones [in the graphic on the website] are the lucky numbers. As you can see, some are prime.
Third, we have "The Magical Qualities of the Number 7."
- Professor Keith Devlin: "If we forget lucky numbers, there is a mathematical notion called a happy number. To get a happy number, you look at the number and you start squaring the digits and adding the answers. If you keep on doing that, eventually either you'll end up with the number one or you will end up getting a sequence of numbers that cycles. It begins 4, 16, 37. Seven is the smallest number that gives you one."
