Williams primes of the form 6•7ⁿ-1

2015-11-13: Checked to n = 200000 , <a href="/z/index.php?title=Robert_Price&amp;action=edit&amp;redlink=1" class="new" title="Robert Price (page does not exist)">Robert Price
2008-11-26: Found n =&#160;67485 - 79326 , <a href="/z/index.php?title=Donovan_Johnson&amp;action=edit&amp;redlink=1" class="new" title="Donovan Johnson (page does not exist)">Donovan Johnson
2006-06-05: Found n =&#160;7167 , Ryan Propper
2003-01-17: Found n =&#160;4214 , <a href="/z/index.php?title=Robert_G._Wilson&amp;action=edit&amp;redlink=1" class="new" title="Robert G. Wilson (page does not exist)">Robert G. Wilson
2001-07-21: Found n =&#160;2930 , <a href="/z/index.php?title=Jason_Earls&amp;action=edit&amp;redlink=1" class="new" title="Jason Earls (page does not exist)">Jason Earls

Current data

1, 2, 7, 18, 55, 69, 87, 119, 141, 189, 249, 354, 1586, 2135, 2865, 2930, 4214, 7167, 67485, 74402, 79326

Remarks :

The sequence A046866 in OEIS