20180429, 19:55  #1 
Nov 2016
3×823 Posts 
OEIS sequence A088782
This sequence is in fact the reversed Sierpinski problem with k=10, according to the thread http://mersenneforum.org/showthread.php?t=10354&page=8, this sequence can be extended to a(184), and a(185) is > 10^6 due to the Sierpinski base 185 problem, and the related sequence A088783 can be added another term 177, since a prime 10*173^264234 is known.
Also the sequence A119624 (the reversed Sierpinski problem with k=2) can be extended to a(364), and A119591 (the reversed Riesel problem with k=2) can be extended to a(580). 
20180430, 06:43  #2 
"Jeppe"
Jan 2016
Denmark
2·3^{4} Posts 
You are absolutely right. This is about primes 10*b^t + 1 for fixed b when t runs from 1 through infinity. You call it reversed Sierpiński?
I am extending A088783 as you suggested (see "History" of the entry until edits are approved). /JeppeSN 
20180430, 14:05  #3  
Nov 2016
9A5_{16} Posts 
Quote:
You can also extend A088782 to n=184, A119624 to n=364, A253178 to n=242 and A119591 to n=580 (by create a bfile). Last fiddled with by sweety439 on 20180430 at 14:05 

20180430, 14:09  #4 
Nov 2016
4645_{8} Posts 
Besides, you can create afiles for these sequences for the status (with some unknown terms, you can use "?" for them and give the test limits) to n=1000.

20180430, 15:21  #5 
"Jeppe"
Jan 2016
Denmark
10100010_{2} Posts 
OK, it is a reference to Krywaruczenko, Daniel (2008) "A Reverse Sierpinski Number Problem," RoseHulman Undergraduate Mathematics Journal: Vol. 9 : Iss. 2 , Article 4. I will fix the link to that paper in OEIS. /JeppeSN

20180430, 19:16  #6 
Nov 2016
3×823 Posts 

20180430, 19:17  #7  
Nov 2016
3×823 Posts 
Quote:


20180430, 22:52  #8 
"Jeppe"
Jan 2016
Denmark
10100010_{2} Posts 
Sweety439, I think you should update those OEIS entries yourself. /JeppeSN

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