Talk:Jordan-Pólya numbers: Difference between revisions

Undo revision 344754 by PureFox (talk) Scrub that last edit as it was working OK before.
(Undo revision 344754 by PureFox (talk) Scrub that last edit as it was working OK before.)
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:There may, of course, be more than one way to decompose a J-P number into a product of factorials but the idea is to choose the way which uses the largest factorials and present these in highest to lowest order. I've added a sentence to the task description to try and clarify this. --[[User:PureFox|PureFox]] ([[User talk:PureFox|talk]]) 09:57, 9 June 2023 (UTC)
:I believe (bicbw) there is no possible way to constructmake 439,378,587,648,000 = 14! * 7! with only prime factorials. --[[User:Petelomax|Petelomax]] ([[User talk:Petelomax|talk]]) 02:53, 10 June 2023 (UTC)
:Yes, your right.14! = 13!*2*7 2= 2! but no way to get a lonely 7. Of course there 16!= 2!^4 * 15! . To much work for to less advantage --[[User:Horst|Horst]] ([[User talk:Horst|talk]]) 16:28, 11 June 2023 (UTC)
 
== Factoring the 1050th number ==
The 1050th jp number is 139,345,920,000. OneIt andfactors Ias suspect7! the* only5!^3 possible* factorisation2!^4 isor 78! * 5!^3 * 2!^4, but the <del>Phix</del>/Julia/Wren entries are not getting that. IUpdate: havenew thoughtalgorithm ofposted, ahowever bettermy strategy,faffing basedabout on thewith prime powers, butis it isprobably not straightforward and would naturally produce the ''lowest'' factorialspoint, one-at- I ''think'' I might have just thought of a-time/less waygreedy toprobably convertis. that--[[User:Petelomax|Petelomax]] to([[User thetalk:Petelomax|talk]]) highest05:31, factorials...10 InJune the2023 meantime, some examples:(UTC)
 
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:Well spotted! Rather than translate yours, I've modified the decomposition algorithm I was using for both Wren versions using recursion and it now seems to be working OK. --[[User:PureFox|PureFox]] ([[User talk:PureFox|talk]]) 11:31, 10 June 2023 (UTC)
92,160 = 6! * 2!^7, or
92,160 = 5! * 3! * 2!^7
18,345,885,696 = 4!^7 * 2!^2, or
18,345,885,696 = 3!^7 * 2!^16
139,345,920,000 = 7! * 5!^3 * 2!^4 (only one?)
18,345,885,696 = 4!^7 * 2!^2, or
18,345,885,696 = 3!^7 * 2!^16
724,775,731,200 = 6! * 5! * 2!^23, or
724,775,731,200 = 5!^2 * 3! * 2!^23
9,784,472,371,200 = 6!^2 * 4!^2 * 2!^15, or
9,784,472,371,200 = 5!^2 * 3!^4 * 2!^19
439,378,587,648,000 = 14! * 4!^2 * 2!^15 (only one?)
7,213,895,789,838,336 = 4!^8 * 2!^16, or
7,213,895,789,838,336 = 3!^8 * 2!^32
</pre>
There are probably only a few ways to do each, maybe show them all? --[[User:Petelomax|Petelomax]] ([[User talk:Petelomax|talk]]) 23:52, 9 June 2023 (UTC)
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