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A 19. Let f(x) = x³ + 17. Prove that for each natural number n ≥ 2, there is a natural
number x for which f(x) is divisible by 3^n but not 3^{n+1}.


来自iPad1楼2013-07-14 15:45回复
    目测递归构造,但没找到


    来自手机贴吧2楼2013-07-14 18:35
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