标题: A fast introduction to these numbers.2, 3, 5, 7, 11, 13, 17, 19, 23, 29 [打印本页] 作者: 厚积薄发 时间: 2013-7-9 10:57 标题: A fast introduction to these numbers.2, 3, 5, 7, 11, 13, 17, 19, 23, 29 2, 3, 5, 7, 11, 13, 17, 19, 23, 29
These are the first 10 prime numbers! An integer n is a prime number if it has no divisors (except for 1 and itself). Another way to say this is that the integer cannot be broken into pieces of equal size. Or you could say that for a prime number the equation n=a*b can never be true, where a and b are integers.
Beginners sometimes get confused by the term "divisor". When mathematicians say that one integer divides another integer they mean with no remainder.
Prime numbers are fundamental numbers due to this fact..
Any integer greater than 2 can be written as a product of prime numbers. So you can think of prime numbers as the "building blocks" from which all numbers are made.
Here are the first 100 prime numbers. The list never stops, and there is no known formula that produces the prime number sequence. Primes are indeed mysterious numbers!
Oh, one more thing. It appears that every even integer greater than 2 can be written as the sum of just two prime numbers, but this incredibly simple proposition has never been proven!
For example: 10=5+5=7+3, and this also shows that there is more than on way an even integer can be written as the sum of two primes. For any even integer n greater than 2 let's define the function g(n)..
g(n)=the number of different ways n can be written as the sum of two primes.
For example, g(10)=2, g(20)=3, g(100)=6
Maybe the function g has some deep significance. Who knows.
不难，工具，时间，努力作者: 1300611016 时间: 2013-12-21 13:05
详细见http://www.madio.net/thread-202136-1-1.html作者: 空木葬花 时间: 2014-3-18 16:42
非常感谢楼主的福利1作者: 专属雨天 时间: 2014-7-3 17:39
看不懂啊看不懂作者: 专属雨天 时间: 2014-7-7 18:17
顶---------------作者: 空空zq 时间: 2014-7-30 09:57
what are you talking about?作者: Zhang_Jiaxing 时间: 2015-1-5 17:37
Maybe "more than on way" should be esplaced with "more than one way".
