jonson

预备知识： palindromic number 回文数字。如：9009.正序与逆序所获取的字符串是一致的。   Question:   A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 9...

What is the smallest number divisible by each of the numbers 1 to 20? [my resolutio]  find the prime number first.beside the prime number ,find every number's smallest factor,then delete the equals ...