判定一个形如2~n—1(n为正整数)的整数是否为梅森素数(见上期第25页),在电子计算机发明之前是一件十分困难的事情.1903年10 月,美国数学家科尔在一次学术会议上走上讲台,在黑板上计算了2~(67)—1,接着,他又将193 707 721和761 838 257 287两个数相乘,两次计算结果完全相同.科尔一言未发,回到了自己的座位上,全场顿时爆发出热烈的掌声,祝贺他证明了2~(67)—1不是梅森素数.(春明) Determining whether an integer of the form 2~n—1 (n is a positive integer) is a Mason prime (see page 25 of last issue) was a very difficult matter before the invention of the computer. In October 1903, the American mathematician Kohl walked up to the podium at an academic conference and calculated 2~(67)–1 on the blackboard. Then he multiplied 193 707 721 and 761 838 257 287, and the two calculations were identical. When Cole returned to his seat without a word, he burst into warm applause and congratulated him on proving that 2~(67)–1 was not a Mason prime. (Chun Ming)