Williams primes of the form 2•3n-1

Reserved! This sequence is currently reserved by: Borys Jaworski

Current data

Base : 3 Count : 37 Max n : 1,840,000 Date : 2019-03-01 Reserved : Borys JaworskiBorys Jaworski/Reserved

1, 2, 3, 7, 8, 12, 20, 23, 27, 35, 56, 62, 68, 131, 222, 384, 387, 579, 644, 1772, 3751, 5270, 6335, 8544, 9204, 12312, 18806, 21114, 49340, 75551, 90012, 128295, 143552, 147488, 1010743, 1063844, 1360104

Remarks :

See H.C.Williams, C.R.Zarnke: "Some prime numbers of the forms 2A3^n+1 and 2A3^n-1" Math. Comp. 26 (1972), 995-998 The sequence A003307 in OEIS

History

• 2019-03-01: Checked to n = 1840000, Borys Jaworski
• 2015-07-31: Found n = 1360104, Borys Jaworski
• 2012-02-12: Found n = 1063844, Borys Jaworski
• 2011-09-01: Found n = 1010743, Borys Jaworski
• 2009-04-12: Checked to n = 570000, David Broadhurst
• 2009-03-09: Checked n = 189000  -  400000, David Broadhurst
• 2004-08-15: Found n = 147488, Ingo Buechel, Wilfrid Keller
• 2004-08-12: Found n = 143552, Ingo Buechel, Wilfrid Keller
• 2003-06-20: Found n = 128295, Ingo Buechel, Wilfrid Keller
• 2001-09-28: Found n = 90012, Wilfrid Keller
• 2001-08-12: Found n = 75551, Wilfrid Keller
• 2001-06-30: Found n = 49340, Wilfrid Keller
• 1972-10: Found n = 1 - 222, Hugh C. Williams, Charles R. Zarnke