Williams primes of the form 8•9ⁿ-1

2016-02-02: Found n =&#160;142199 , <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
2014-03-16: Found n =&#160;17978 - 95305 , <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
?: Found n =&#160;4985 , <a href="/z/index.php?title=Douglas_Burke&amp;action=edit&amp;redlink=1" class="new" title="Douglas Burke (page does not exist)">Douglas Burke

Current data

1, 2, 5, 25, 85, 92, 97, 649, 2017, 2978, 3577, 4985, 17978, 21365, 66002, 95305, 142199

Remarks :

Should be (re)used from 8•3ⁿ-1.
The sequence A268356 in OEIS and halved even values of sequence A005541 in OEIS