ON FINITE SUMS OF RECIPROCALS OF DISTINCT nTR POWERS

نویسنده

  • R. L. GRAHAM
چکیده

Introduction* It has long been known that every positive rational number can be represented as a finite sum of reciprocals of distinct positive integers (the first proof having been given by Leonardo Pisano [6] in 1202). It is the purpose of this paper to characterize {cf. Theorem 4) those rational numbers which can be written as finite sums of reciprocals of distinct nth. powers of integers, where n is an arbitrary (fixed) positive integer and "finite sum" denotes a sum with a finite number of summands. It will follow, for example, that p\q is the finite sum of reciprocals of distinct squares if and only if

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تاریخ انتشار 2004