找规律,求第N项:3,13,21,23,33,41,43,53,63,63.3,13,21,23,33,41,43,53,63,63,73,83,91,93.103,111,113,123,133,133,143,153,161,163,173,181,183,193,203,203,213.我觉得应该分成两段来求.可就是找不出..
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![找规律,求第N项:3,13,21,23,33,41,43,53,63,63.3,13,21,23,33,41,43,53,63,63,73,83,91,93.103,111,113,123,133,133,143,153,161,163,173,181,183,193,203,203,213.我觉得应该分成两段来求.可就是找不出..](/uploads/image/z/5267541-21-1.jpg?t=%E6%89%BE%E8%A7%84%E5%BE%8B%2C%E6%B1%82%E7%AC%ACN%E9%A1%B9%3A3%2C13%2C21%2C23%2C33%2C41%2C43%2C53%2C63%2C63.3%2C13%2C21%2C23%2C33%2C41%2C43%2C53%2C63%2C63%2C73%2C83%2C91%2C93.103%2C111%2C113%2C123%2C133%2C133%2C143%2C153%2C161%2C163%2C173%2C181%2C183%2C193%2C203%2C203%2C213.%E6%88%91%E8%A7%89%E5%BE%97%E5%BA%94%E8%AF%A5%E5%88%86%E6%88%90%E4%B8%A4%E6%AE%B5%E6%9D%A5%E6%B1%82.%E5%8F%AF%E5%B0%B1%E6%98%AF%E6%89%BE%E4%B8%8D%E5%87%BA..)
找规律,求第N项:3,13,21,23,33,41,43,53,63,63.3,13,21,23,33,41,43,53,63,63,73,83,91,93.103,111,113,123,133,133,143,153,161,163,173,181,183,193,203,203,213.我觉得应该分成两段来求.可就是找不出..
找规律,求第N项:3,13,21,23,33,41,43,53,63,63.
3,13,21,23,33,41,43,53,63,63,73,83,91,93.103,111,113,123,133,133,143,153,161,163,173,181,183,193,203,203,213.
我觉得应该分成两段来求.可就是找不出..
找规律,求第N项:3,13,21,23,33,41,43,53,63,63.3,13,21,23,33,41,43,53,63,63,73,83,91,93.103,111,113,123,133,133,143,153,161,163,173,181,183,193,203,203,213.我觉得应该分成两段来求.可就是找不出..
第3项是21,6项是41,13项是91,16项是111,23项是161,26项是181可以推出当n的尾数是3的时候,第n项是7n;当n的尾数是6的时候,第n项是7n-1.
尾数是2的是7n-8,尾数是1的是7n-4,尾数是4的是7n-5,尾数是5的是7n-2,尾数是7的是7n-6,尾数是8的是7n-3,尾数是9的是7n,尾数是0的是7n-7
(上面第二行和第三行的n要大于等于2.第一次遇到这种题,希望不会出现错误)