Prime found, k=168451 eliminated

[JimB]

On 2017-09-17 at 21:30 PrimeGrid user Ben Maloney returned the following result:

168451*2^19375200+1 is prime! (5832522 decimal digits). That prime eliminates k=168451 from the Prime Sierpinski Problem. The prime will show up on http://www.primegrid.com/stats_psp_llr.php as soon as the Top 5000 Primes site verifies it.

[LaurV]

Originally Posted by JimB

On 2017-09-17 at 21:30 PrimeGrid user Ben Maloney returned the following result:

168451*2^19375200+1 is prime! (5832522 decimal digits). That prime eliminates k=168451 from the Prime Sierpinski Problem. The prime will show up on http://www.primegrid.com/stats_psp_llr.php as soon as the Top 5000 Primes site verifies it.

Yarrrrr!

Congrats! A very-very nice top finding!

[MisterBitcoin]

Let´s make a


What a nice finding by PG!

[Citrix]

Great news!

[Dr Sardonicus]

In the sciencealert page about the discovery that 10,223*2^31172165 + 1 is prime dated November 28, 2016 it says (my emphasis)

In fact, among the 10 largest known prime numbers, our new prime is the only prime that is not a Mersenne number, and the only known non-Mersenne prime over 4 million digits.

Though this new discovery isn't large enough to displace any of the "top ten known primes," that last phrase has gone out of date.

Also, it looks to be the new #13 at THE LARGEST KNOWN PRIMES (Primes with 600,000 or more digits) list -- which was just updated!

The letters after the rank refer to when the prime was submitted.
'a' is this month, 'b' last month...
----- ------------------------------- -------- ----- ---- --------------
rank description ___________ digits __ who __ year comment
----- ------------------------------- -------- ----- ---- --------------
12a 919444^1048576+1 ____ 6253210 L4286 2017 Generalized Fermat
13 Phi(3,-123447^524288) __ 5338805 L4561 2017 Generalized unique

Congratulations!

[axn]

Originally Posted by Dr Sardonicus

Though this new discovery isn't large enough to displace any of the "top ten known primes," that last phrase has gone out of date.

That went out of date in Jan 2017

[Dr Sardonicus]

Originally Posted by axn

That went out of date in Jan 2017

Check. That was Phi(3, - 143332393216) with 4055114 decimal digits.

Curiously, that page lists its rank as 15, which is correct given the new discovery that is the subject of this thread. The short list I provided the link to does not have the new discovery yet, so lists the rank as 14.

[sweety439]

Another 3 k's eliminated:

90527 (90527*2^9162167+1)
258317 (258317*2^5450519+1)
265711 (265711*2^4858008+1)

Now only 7 primes > 78557 remain:

79309, 79817, 152267, 156511, 222113, 225931, 237019