On the largest prime factor of n ! + 2 n - 1

Florian Luca[1]; Igor E. Shparlinski[2]

  • [1] Instituto de Matemáticas Universidad Nacional Autónoma de México C.P. 58089, Morelia, Michoacán, México
  • [2] Macquarie University Sydney, NSW 2109, Australia

Journal de Théorie des Nombres de Bordeaux (2005)

  • Volume: 17, Issue: 3, page 859-870
  • ISSN: 1246-7405

Abstract

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For an integer n 2 we denote by P ( n ) the largest prime factor of n . We obtain several upper bounds on the number of solutions of congruences of the form n ! + 2 n - 1 0 ( mod q ) and use these bounds to show that lim sup n P ( n ! + 2 n - 1 ) / n ( 2 π 2 + 3 ) / 18 .

How to cite

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Luca, Florian, and Shparlinski, Igor E.. "On the largest prime factor of $n!+ 2^n-1$." Journal de Théorie des Nombres de Bordeaux 17.3 (2005): 859-870. <http://eudml.org/doc/249430>.

@article{Luca2005,
abstract = {For an integer $n\ge 2$ we denote by $P(n)$ the largest prime factor of $n$. We obtain several upper bounds on the number of solutions of congruences of the form $n!+2^n - 1 \equiv 0 \hspace\{4.44443pt\}(\@mod \; q)$ and use these bounds to show that\[\limsup \_\{n \rightarrow \infty \}P(n!+2^n - 1)/n \ge (2 \pi ^2 + 3)/18. \]},
affiliation = {Instituto de Matemáticas Universidad Nacional Autónoma de México C.P. 58089, Morelia, Michoacán, México; Macquarie University Sydney, NSW 2109, Australia},
author = {Luca, Florian, Shparlinski, Igor E.},
journal = {Journal de Théorie des Nombres de Bordeaux},
keywords = {largest prime factor; number of distinct prime factors; number of solutions of congruences},
language = {eng},
number = {3},
pages = {859-870},
publisher = {Université Bordeaux 1},
title = {On the largest prime factor of $n!+ 2^n-1$},
url = {http://eudml.org/doc/249430},
volume = {17},
year = {2005},
}

TY - JOUR
AU - Luca, Florian
AU - Shparlinski, Igor E.
TI - On the largest prime factor of $n!+ 2^n-1$
JO - Journal de Théorie des Nombres de Bordeaux
PY - 2005
PB - Université Bordeaux 1
VL - 17
IS - 3
SP - 859
EP - 870
AB - For an integer $n\ge 2$ we denote by $P(n)$ the largest prime factor of $n$. We obtain several upper bounds on the number of solutions of congruences of the form $n!+2^n - 1 \equiv 0 \hspace{4.44443pt}(\@mod \; q)$ and use these bounds to show that\[\limsup _{n \rightarrow \infty }P(n!+2^n - 1)/n \ge (2 \pi ^2 + 3)/18. \]
LA - eng
KW - largest prime factor; number of distinct prime factors; number of solutions of congruences
UR - http://eudml.org/doc/249430
ER -

References

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  4. P. Erdős, C. Stewart, On the greatest and least prime factors of n ! + 1 . J. London Math. Soc. 13 (1976), 513–519. Zbl0332.10028MR409334
  5. É. Fouvry, Théorème de Brun-Titchmarsh: Application au théorème de Fermat. Invent. Math. 79 (1985), 383–407. Zbl0557.10035MR778134
  6. H.-K. Indlekofer, N. M. Timofeev, Divisors of shifted primes. Publ. Math. Debrecen 60 (2002), 307–345. Zbl1017.11042MR1898566
  7. F. Luca, I. E. Shparlinski, Prime divisors of shifted factorials. Bull. London Math. Soc. 37 (2005), 809–817. Zbl1098.11047MR2186713
  8. M.R. Murty, S. Wong, The A B C conjecture and prime divisors of the Lucas and Lehmer sequences. Number theory for the millennium, III (Urbana, IL, 2000), A K Peters, Natick, MA, 2002, 43–54. Zbl1030.11012MR1956267
  9. F. Pappalardi, On the order of finitely generated subgroups of * ( mod p ) and divisors of p - 1 . J. Number Theory 57 (1996), 207–222. Zbl0847.11049MR1382747
  10. K. Prachar, Primzahlverteilung. Springer-Verlag, Berlin, 1957. Zbl0080.25901MR87685

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