DOI QR코드

DOI QR Code

A CLASS OF NEW NEAR-PERFECT NUMBERS

  • LI, YANBIN (Institute of Mathematics and Software Science Sichuan Normal University) ;
  • LIAO, QUNYING (Institute of Mathematics and Software Science Sichuan Normal University)
  • Received : 2014.08.19
  • Published : 2015.06.01

Abstract

Let ${\alpha}$ be a positive integer, and let $p_1$, $p_2$ be two distinct prime numbers with $p_1$ < $p_2$. By using elementary methods, we give two equivalent conditions of all even near-perfect numbers in the form $2^{\alpha}p_1p_2$ and $2^{\alpha}p_1^2p_2$, and obtain a lot of new near-perfect numbers which involve some special kinds of prime number pairs. One kind is exactly the new Mersenne conjecture's prime number pair. Another kind has the form $p_1=2^{{\alpha}+1}-1$ and $p_2={\frac{p^2_1+p_1+1}{3}}$, where the former is a Mersenne prime and the latter's behavior is very much like a Fermat number.

Keywords

References

  1. P. T. Bateman, J. L. Selfridge, and S. S. Wagstaff Jr., The new Mersenne conjecture, Amer. Math. Monthly 96 (1989), no. 2, 125-128. https://doi.org/10.2307/2323195
  2. R. P. Brent, G. L. Cohen, and H. J. J. te Riele, Improved techniques for lower bounds for odd perfect numbers, Math. Comp. 57 (1991), no. 196, 857-868. https://doi.org/10.1090/S0025-5718-1991-1094940-3
  3. M. M. Buxton and S. R. Elmore, An extension of lower bounds for odd perfect numbers, Not. Amer. Math. Soc. 23 (1976), A-55.
  4. S. A. Fletcher, P. P. Nielsen, and P. Ochem, Sieve methods for odd perfect numbers, Math. Comp. 81 (2012), no. 279, 1753-1776. https://doi.org/10.1090/S0025-5718-2011-02576-7
  5. G. H. Hardy and E. M. Wright, An Introduction to the Theory of Numbers, 6th Edition, Oxford Science Publishers, 2003.
  6. K. Ireland and M. Ira Rosen, A Classical Introduction to Modern Number Theory, 2nd Edition, Springer, 1990.
  7. P. Ochem and M. Rao, Odd perfect numbers are greater than 101500, Math. Comp. 81 (2012), no. 279, 1869-1877. https://doi.org/10.1090/S0025-5718-2012-02563-4
  8. P. Pollack and V. Shevelev, On perfect and near-perfect numbers, J. Number Theory 132 (2012), no. 12, 3037-3046. https://doi.org/10.1016/j.jnt.2012.06.008
  9. X. Z. Ren and Y. G. Chen, On near-perfect numbers with two distinct prime factors, Bull. Austral. Math. Soc. 88 (2013), no. 3, 520-524. https://doi.org/10.1017/S0004972713000178
  10. W. Sierpinski, Sur les nombres pseudoparfaits, Mat. Vesnik 17 (1965), 212-213.
  11. N. J. Sloane, The online encyclopedia of integer sequences, accessible at http://oeis.org.
  12. B. Stubblefield, Greater lower bounds for odd perfect numbers, Env. Res. Lab. NOAA (1977), 209.
  13. M. Tang, X. Z. Ren, and M. Li, On near-perfect and deficient-perfect numbers, Colloq. Math. 133 (2013), no. 2, 221-226. https://doi.org/10.4064/cm133-2-8