IntroductionThe problem of the representation of power-free integers by integral polynomials appears to have been first considered by Nageil [8], who shewed in 1922 that an irreducible polynomial f(n) of degree r > 2 is Z-free (i. e. not divisible by an Z-th power other than 1) for infinitely many n provided / ^ r. This work was subsequently refined and developed by a number of writers, among whom we may mention Ricci, Estermann, Atkinson and Lord Gherwell, and Erdös. Using a sieve method Ricci [9], for example, proved in 1933 that, if N (x) -N (/, /) be the number of positive integers n not exceeding with the property that f(n) be /-free, then the asymptotic formulaäs -> oo, is valid for / > r. Estermann [5] had, however, already derived by another method a similar but more precise asymptotic formula for N(#) in the special case for which f(n) = n 2 + k and / = 2, while much later Atkinson and Lord Cherwell [1], independently of Estermann, proved an analogous formula for the less restricted special case f(n) = n r + k and l -r. Several other papers also appeared between the publication of Ricci's paper and 1953, but these, though of interest in many respects, did not substantially contribute to the solution of the main problem because they did not relate to the difficult case l < r. In the latter year Erdös [4] made a significant advance by proving in a characteristically ingenious manner that NagelPs result is true when l -r -l (r > 2) provided that the obvious necessary condition that f(n) have no (r -l)th power fixed divisors hold. His method, however, did not provide an asymptotic formula for N(#), nor did it shew that the integers n for which f(n) is (r -l)-free had positive upper or lower densities. Indeed, äs Erdös observed, the state of knowledge about the case l < r was still quite incomplete since it was not even known whether a particular quartic polynomial such äs r£ + 2 could be infinitely often square-free or whether for l = 2 Ricci's asymptotic formula held for any cubics at all 1 ).The purpose of this paper is to prove that the asymptotic formula z \ Iog 8 # !) A closely allied problem is that of the representation of large numbers äs the sum of an rth power and an Z-free number. A proof of an asymptotic formula for the number of representations has been attempted by Subhankulov and Moisezon without restriction on r and l (Izv.