Zentralblatt MATH
Publications of (and about) Paul Erdös
Zbl.No: 127.26706
Autor: Erdös, Pál
Title: On note 2921 (In English)
Source: Math. Gaz. 45, 39 (1961).
Review: The note in question (by Morley) contains a conjecture originally proposed by Catalan that if 2n-1 = p is prime, then 2p-1 is also prime. The author reports a computer result to show the falsity of the conjecture for n = 13, where 213-1 = 8191 is prime but 28191-1 is composite.
Reviewer: W.E.Briggs
Classif.: * 11A51 Factorization of numbers
Index Words: number theory
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