Continued fractions with sequences of partial quotients
Continued fractions with sequences of partial quotients
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DOI:
10.1090/s0002-9939-1973-0311581-4
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发表时间:
1973-02
期刊:
影响因子:
--
通讯作者:
K. Hirst
中科院分区:
文献类型:
--
作者:
K. Hirst
Three results are proved concerning the Hausdorff fractional dimension of sets of continued fractions whose partial quotients belong to given sequences. Introduction. In [1], I. J. Good investigated the fractional dimension of sets of continued fractions whose partial quotients an obey various conditions. Included amongst these results are theorems discussing cases where an becomes large, and in [2] these results were extended to cover some cases where an tends to infinity rapidly. In all these results the only restrictions on an are of the type an_f(n) and an--oo. In this paper I shall prove analogous results concerning the cases where an is further restricted to belong to some sequence of natural numbers. The notation to be used and the relevant parts of the theories of continued fractions and Hausdorff measures are given in [2] and the reader is referred to that paper for these details. In addition throughout the paper we shall use (bn) to denote a strictly increasing sequence of natural numbers (rather than (+(n))-for ease of printing). The following theorems will be proved. THEOREM 1. Suppose the series E (on)-' converges. Then provided A has the property that >,(on)" -A the set E={jai.>A and ai E (bn)} has fractional dimension _ ?cx. THEOREM 2. Suppose the series E (bn)-' diverges. Then for any A, the set E in Thleorem 1 has dimension 1ac.