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7个数字有多少种排列1.2.3.4.5.7.7个数字 列:7654321 7564321 7465321 .123456

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7个数字有多少种排列
1.2.3.4.5.7.7个数字 列:7654321 7564321 7465321 .1234567..1236547 这样不重复的排列有多少
7个数字有多少种排列1.2.3.4.5.7.7个数字 列:7654321 7564321 7465321 .123456
1234567.1234576.1234657.1234675.1234756.1234765.1235467.1235476.1235647.1235674..1236457.1236475.1236547.1236574.1237456.1237465.1237546.1237564.1243567.1243576.1243657.1243657.1243675.1243756.1243765.1245367.1245376.1245637.1245673.1245736.1245763.1246357.1246375.1246537.1246573.1246735.1246753.1247356.1247365.1247536.1247563.1247636.1247653.1324567.1324576.1324657.1324675.1324756.1324765.1325467.1325476.1325647.1325674.1325746.1325764.1326457.1326475.1326547.1326574.1326754.1326745.1327456.1327465.1327546.1327564.1327645.1327654.134...倒137 ..每个24中 好有134..135..136..137...还有4个 共96个 倒现在为止有160种排列了 在把开头1 换2...3...4..5...6...7 等于160*7=1020种排列