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Williams prime MM 5
| Reserved! This sequence is currently reserved by: User:Karbon |
Definition
Williams prime (b-1)× bn-1 with b = 5 (primes of the form 4 × 5n-1, n ≥ 1).
Prime for n
1, 3, 9, 13, 15, 25, 39, 69, 165, 171, 209, 339, 2033, 6583, 15393, 282989, 498483, 504221, 754611, 864751
Search range
n = 905000 (2019-03-07)
History
| Date | Remark |
|---|---|
| 2019-02-23 | found n = 864751, Karsten Bonath |
| 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 |
External links
- Williams number
- Thread at MersenneForum
- The sequence A046865 in OEIS
