mersenneforum.org  

Go Back   mersenneforum.org > Fun Stuff > Lounge

Reply
 
Thread Tools
Old 2020-10-01, 20:04   #419
mart_r
 
mart_r's Avatar
 
Dec 2008
you know...around...

60910 Posts
Default

Quote:
Originally Posted by Dr Sardonicus View Post
the smallest gap size (difference of consecutive primes) whose first occurrence is not yet definitely known.
Perfectly correct!

Still don't have a clue regarding 20287, I'm afraid. Maybe tomorrow I wake up shouting "Heureka!"...
mart_r is offline   Reply With Quote
Old 2020-10-01, 22:31   #420
tuckerkao
 
Jan 2020

2·32·7 Posts
Default

Quote:
Originally Posted by mart_r View Post
Perfectly correct!

Still don't have a clue regarding 20287, I'm afraid. Maybe tomorrow I wake up shouting "Heureka!"...
I prefer 20736 because it's the whole power of something fundamental.
tuckerkao is online now   Reply With Quote
Old 2020-10-12, 08:01   #421
R2357
 
"Ruben"
Oct 2020
Nederland

2×19 Posts
Smile 48

I saw 48 a bit above,
Possible Prime Positions for 7#




New number 987654103
R2357 is offline   Reply With Quote
Old 2020-10-12, 09:51   #422
Viliam Furik
 
Jul 2018
Martin, Slovakia

271 Posts
Default

Quote:
Originally Posted by R2357 View Post
I saw 48 a bit above,
Possible Prime Positions for 7#




New number 987654103
Something in the sense of: Biggest prime containing unique decimal digits.

Such number can't contain all the digits because then it would be multiple of 9.
Viliam Furik is online now   Reply With Quote
Old 2020-10-12, 10:53   #423
R2357
 
"Ruben"
Oct 2020
Nederland

2·19 Posts
Thumbs up Good

Yes, that's right!
R2357 is offline   Reply With Quote
Old 2020-10-12, 11:47   #424
R2357
 
"Ruben"
Oct 2020
Nederland

2×19 Posts
Smile oops

I forgot to post the next number :

30 031
R2357 is offline   Reply With Quote
Old 2020-10-13, 01:33   #425
Dr Sardonicus
 
Dr Sardonicus's Avatar
 
Feb 2017
Nowhere

22·3·52·13 Posts
Default

Quote:
Originally Posted by Dr Sardonicus View Post
I came up with the following number when musing about a recent announcement:

20287
The time has come. The "recent announcement" was that Amazon Prime Day would be October 13-14 this year. I wondered about associating either day with a prime number in some way.

Of course, the day-of-month 13 is prime. But I wondered if there was a way to associate either complete date, October 13 or 14, 2020, with a prime number.

And lo and behold, the Julian Date of October 13, 2020 is 20287. And 20287 is a prime number.
Dr Sardonicus is offline   Reply With Quote
Old 2020-10-13, 02:19   #426
retina
Undefined
 
retina's Avatar
 
"The unspeakable one"
Jun 2006
My evil lair

23×11×67 Posts
Default

Quote:
Originally Posted by Dr Sardonicus View Post
... the Julian Date of October 13, 2020 is 20287.
WP disagrees. It isn't even close.
retina is offline   Reply With Quote
Old 2020-10-13, 12:41   #427
Dr Sardonicus
 
Dr Sardonicus's Avatar
 
Feb 2017
Nowhere

22·3·52·13 Posts
Default

Quote:
Originally Posted by retina View Post
Quote:
Originally Posted by Dr Sardonicus View Post
... the Julian Date of October 13, 2020 is 20287.
WP disagrees. It isn't even close.
The term "Julian Date" (as opposed to Julian Day) is commonly used to mean the ordinal date, or day number in the current year. The day number of October 13 this year (a leap year) is 287. Prepending the last two digits of the year number gives the "Julian Date" in YYDDD format, here, 20287. Another common format is YYYY-DDD.

The Julian Day (number) is the number of days (including fractional part) since the beginning of the "Julian period" which is (12:00) January 1, 4713 BC, somewhat over 6000 years ago. The number of days in 6000 years is a bit larger than 6000x360 = 2160000. The Julian Day Number for (00:00) October 13, 2020 is 2459135.5 (nearest primes 2459129 and 245941).

There is also a "Modified Julian Day Number," which subtracts 2,400,000.5 from the Julian Day Number, shifting the starting date to November 17, 1858 and the start time from Noon to Midnight.

The Modified Julian Day Number for (00:00) October 13, 2020 is 59135 (nearest primes 59123 and 59141).
Dr Sardonicus is offline   Reply With Quote
Old 2020-10-13, 12:44   #428
R2357
 
"Ruben"
Oct 2020
Nederland

2·19 Posts
Default

I thought this thread was about finding particularities in the posted number and post a number...
R2357 is offline   Reply With Quote
Old 2020-10-13, 13:09   #429
retina
Undefined
 
retina's Avatar
 
"The unspeakable one"
Jun 2006
My evil lair

23×11×67 Posts
Default

Quote:
Originally Posted by R2357 View Post
I thought this thread was about finding particularities in the posted number and post a number...
Okay. Here is a number: 314159265
retina is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Do you think you're special? MooMoo2 Lounge 26 2016-05-06 20:35
Special Smooth numbers Citrix Other Mathematical Topics 46 2012-03-06 14:55
Special Circumstances xilman Soap Box 5 2009-06-05 08:20
Special n kar_bon Riesel Prime Data Collecting (k*2^n-1) 1 2009-02-19 04:28
am i special yet? jeffowy Miscellaneous Math 2 2003-12-17 21:40

All times are UTC. The time now is 23:52.

Sat Dec 5 23:52:01 UTC 2020 up 2 days, 20:03, 0 users, load averages: 1.93, 1.75, 1.73

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.