a^2 - b^2 = (a-b)(a+b)
所以看195的约数
195 = 5 * 3 * 13
= 1 * 195 =98^2 - 97^2
= 3 * 65 = 34^2 - 31^2
= 5 * 39 = 22^2 - 17^2
= 13 * 15 = 14^2 - 1^2
a^2 - b^2 = (a-b)(a+b)
所以看195的约数
195 = 5 * 3 * 13
= 1 * 195 =98^2 - 97^2
= 3 * 65 = 34^2 - 31^2
= 5 * 39 = 22^2 - 17^2
= 13 * 15 = 14^2 - 1^2