[QUOTE=mfgoode]:ermm: :smile:

rank / prime / digits / who / when comment
1 / 2^ [(22478785)^(3)] +1 / 746190 / g245 / Oct 2003 / Divides

Fermat F(2478782), GF(2478782,3), GF(2478776,6), GF(2478782,12)
Mally :coffee:[/QUOTE]

I seem to always arrive to this thread at bad times, but this appears to be an answer to the last posted number with no follow-up number attached?

Special whole numbers
 

[QUOTE=tom11784]I seem to always arrive to this thread at bad times, but this appears to be an answer to the last posted number with no follow-up number attached?[/QUOTE]
:surprised
Very well Tom. Its good you brought us back on topic.
Quote:
Originally Posted by mfgoode
Your number 196883: =196,560 + 323
196,560 is the number of spheres touching any one sphere in a 24-dimensional Leech lattice
323 = 17*19
However let's have your answer wpolly so the number is up again
196883.
Mally
The next number: 2478782
This number is answered in your Quote Tom

The next number is 481899 :
Mally :coffee:

[QUOTE=mfgoode]:surprised
Very well Tom. Its good you brought us back on topic.
Quote:
Originally Posted by mfgoode
Your number 196883: =196,560 + 323
196,560 is the number of spheres touching any one sphere in a 24-dimensional Leech lattice
323 = 17*19
However let's have your answer wpolly so the number is up again
196883.
Mally
The next number: 2478782
This number is answered in your Quote Tom

The next number is 481899 :
Mally :coffee:[/QUOTE]

The largest n for which it is known that n*2^n+1 is prime (the largest known Cullen prime)

Here it goes: 454539357304421

[QUOTE=fetofs]Here it goes: 454539357304421[/QUOTE]
Google makes these sorts of challenges too easy. Rather than hide things in SPOILER tags, I'll post the URL and you can decide whether nor not you want to click on it.

[url]http://www.greenhodge.net/g/read/math/numbers-6.php[/url]

Here's an obscure one, but you can find out the property I have in mind if you are an assiduous searcher and if I tell you it has personal significance to me. That should be all the clue you need.

191715

Paul

Special whole numbers
 

:surprised
Thanks Paul.
Your URL adds the death knell and fun to all our challenges once and for all.
I took my number which fetofs answered from 'The little book of bigger primes'. by Paulo Ribenboim. There are many in there which perhaps Google cant give so I'll try.
There are many of my originals which I have kept pending thinking I may let mersenneforum have my formulae. But since Im being labelled a crank I hesitate to divulge them. For instance a chip algorithm on logic, the one for 666 etc.etc.. all mathematically precise and sound-no cranky business here!
Time will tell.
Mally :coffee:
P.S. your number which I remember by heart and no checking back :showoff:
191715

[QUOTE=xilman]Google makes these sorts of challenges too easy. Rather than hide things in SPOILER tags, I'll post the URL and you can decide whether nor not you want to click on it.

[url]http://www.greenhodge.net/g/read/math/numbers-6.php[/url]

Here's an obscure one, but you can find out the property I have in mind if you are an assiduous searcher and if I tell you it has personal significance to me. That should be all the clue you need.

191715

Paul[/QUOTE]

Maybe it's not so important, but I'll post it anyway:

[url]http://it.slashdot.org/~Xilman/[/url]

[QUOTE=fetofs]Maybe it's not so important, but I'll post it anyway:

[url]http://it.slashdot.org/~Xilman/[/url][/QUOTE]
Yeah. It really is time I posted more to my Journal.


Paul

[QUOTE=fetofs]The largest n for which it is known that n*2^n+1 is prime (the largest known Cullen prime)[/QUOTE]

Not quite. It was until earlier this year. 1354828*2^1354828+1, aka 338707*2^1354830+1 on the Prime Pages is the current record.

[QUOTE=ewmayer]The number of the statutory instrument governing production of fresh meat products in Great Britain:

[url]http://www.hmso.gov.uk/si/si1995/Uksi_19950539_en_1.htm[/url]

Isn't Google great? :D

5171655946[/QUOTE]

Google is really great!

ln (2^(2^31 * 554189328) / ln 10 = 5171655946


New number 251

Special whole numbers.
 

:smile:
251 is the smallest number that is the sum of 3 different cubes in 2 ways
251 = 1^3 +5 ^3 + 5^3 = 2 ^ 3 + 3 ^3 + 6 ^ 3.
I give two numbers each distinctive in their own ways and mathematically connected to each other. This is a good one for you fetofs as its original.
137
3425
Mally :coffee:

[QUOTE=rogue]Not quite. It was until earlier this year. 1354828*2^1354828+1, aka 338707*2^1354830+1 on the Prime Pages is the current record.[/QUOTE]

Oh yeah. I forgot.