Alternating Factorials - Page 2

rogue · 2017-08-14, 14:54

Quote:

Originally Posted by ericw

https://oeis.org/A100289
Numbers n such that (1!)^2 + (2!)^2 + (3!)^2 +...+ (n!)^2 is prime.
a(19) = 32841 from Serge Batalov, Jul 29 2017

I'll probably leave that one alone. I haven't working on it.

rogue · 2017-08-15, 14:59

Sieving completed a couple of days ago. I've tested to n=30000 and have verified known results. I should reach Serge's find by the end of the week.

rogue · 2017-08-18, 15:02

I've tested to n=40000 and have verified known results.

rogue · 2017-08-23, 12:50

I've tested to n=50000 and have verified known results, including Serge's find. Continuing.

rogue · 2017-08-31, 16:37

I've tested to n=60000. No new PRPs.

rogue · 2017-09-14, 02:07

I've tested to n=70000. No new PRPs.

rogue · 2017-09-18, 15:22

I don't know how I missed this one. The 25th term is for n=59961 which is 260447 digits (if I calculated that correctly).

The search is around n=74000. I'm not certain how much further I'm going to search, but I have sieved to n=100000.

rogue · 2017-10-23, 13:30

After a hiatus, I've tested to n=80000. No new PRPs.

rogue · 2017-11-15, 15:05

Completed to 90000. No new PRPs. Continuing.

CRGreathouse · 2017-11-15, 19:53

Quote:

Originally Posted by rogue

I don't know how I missed this one. The 25th term is for n=59961 which is 260447 digits (if I calculated that correctly).

Great! (I verified that it's 3-prp.) I see that you've added it to A001272.

ericw · 2017-11-20, 14:02

Quote:

Originally Posted by rogue

I don't know how I missed this one. The 25th term is for n=59961 which is 260447 digits (if I calculated that correctly).

(Actually 260448 decimal digits.)

Congratulations again :)

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2017-08-15, 14:59	#13
rogue "Mark" Apr 2003 Between here and the 11×577 Posts	Sieving completed a couple of days ago. I've tested to n=30000 and have verified known results. I should reach Serge's find by the end of the week.

2017-08-18, 15:02	#14
rogue "Mark" Apr 2003 Between here and the 6347₁₀ Posts	I've tested to n=40000 and have verified known results.

2017-08-23, 12:50	#15
rogue "Mark" Apr 2003 Between here and the 1100011001011₂ Posts	I've tested to n=50000 and have verified known results, including Serge's find. Continuing.

2017-08-31, 16:37	#16
rogue "Mark" Apr 2003 Between here and the 14313₈ Posts	I've tested to n=60000. No new PRPs.

2017-09-14, 02:07	#17
rogue "Mark" Apr 2003 Between here and the 6347₁₀ Posts	I've tested to n=70000. No new PRPs.

2017-09-18, 15:22	#18
rogue "Mark" Apr 2003 Between here and the 11×577 Posts	I don't know how I missed this one. The 25th term is for n=59961 which is 260447 digits (if I calculated that correctly). The search is around n=74000. I'm not certain how much further I'm going to search, but I have sieved to n=100000.

2017-10-23, 13:30	#19
rogue "Mark" Apr 2003 Between here and the 6347₁₀ Posts	After a hiatus, I've tested to n=80000. No new PRPs.

2017-11-15, 15:05	#20
rogue "Mark" Apr 2003 Between here and the 6347₁₀ Posts	Completed to 90000. No new PRPs. Continuing.