| 释义 | Lehmer's ProblemDo there exist any Composite Numbers  such that  ?  No such numbers areknown.  In 1932, Lehmer showed that such an  must be Odd and Squarefree, and that the number of distinctPrime factors  . This was subsequently extended to  . The best current results are  and  (Cohen and Hagis 1980), if  , then  (Wall 1980), and if  then  and  (Lieuwens 1970). References
 Cohen, G. L. and Hagis, P. Jr.  ``On the Number of Prime Factors of  is  .''  Nieuw Arch. Wisk. 28, 177-185, 1980. Lieuwens, E.  ``Do There Exist Composite Numbers for which  Holds?''  Nieuw. Arch. Wisk.  18, 165-169, 1970. Ribenboim, P.  The Book of Prime Number Records, 2nd ed.  New York: Springer-Verlag, pp. 27-28, 1989. Wall, D. W.  ``Conditions for  to Properly Divide  .''  In A Collection of Manuscripts Related to the Fibonacci Sequence  (Ed. V. E. Hoggatt and M. V. E. Bicknell-Johnson).  San Jose, CA: Fibonacci Assoc., pp. 205-208, 1980. 
 |