Currently there may be errors shown on top of a page, because of a missing Wiki update (PHP version and extension DPL3).
Navigation
Topics Help • Register • News • History • How to • Sequences statistics • Template prototypes

Williams prime MM 5

From Prime-Wiki
Revision as of 14:48, 4 February 2019 by Karbon (talk | contribs)
Jump to: navigation, search
Reserved! This sequence is currently reserved by: User:Karbon

Definition

Primes of the form [math]\displaystyle{ 4 \cdot {5^n{-}1} }[/math], n ≥ 1.

Primes for n

1, 3, 9, 13, 15, 25, 39, 69, 165, 171, 209, 339, 2033, 6583, 15393, 282989, 498483, 504221, 754611

Search range

765000 (2019-01-30)

History

Date Remark
2019-01-27 found n = 754611, Karsten Bonath
2018-12-24 found n = 504221, Karsten Bonath
2018-12-23 found n = 498483, Karsten Bonath
2018-12-06 Checked to n = 1 - 321000, found n = 282989, Karsten Bonath
2007-20-12 Checked to n = 200000, Geoff Reynolds
2007-07-13 Checked to n = 110000, Geoff Reynolds
2006-08 Found n = 15393, antiroach
1981 Checked to n = 500, found n = 1 ... 339, H. C. Williams

See also

External links