Re: 15! permutations
- To: mathgroup at smc.vnet.net
- Subject: [mg108694] Re: 15! permutations
- From: János Löbb <janos.lobb at yale.edu>
- Date: Sat, 27 Mar 2010 05:12:44 -0500 (EST)
On Mar 26, 2010, at 6:35 AM, Nicola Mingotti wrote: > On 2010-03-25 12:11:52 +0100, bn77 said: > >> Hi, >> >> I'm trying to write a program in mathematica that compares roughly >> (15!)^2 / 2 pairs of permutations of length 15. Can mathematica do >> this >> in a reasonable time? Any experience of this sort? >> >> TIA, >> bn77 > > The number of permutations is then : > N[((15!)^2)/2] ==> 8.55006*10^23 > > Supposing you can compare 10^9 objects per second > you would need 10^4 seconds that is 3.171 milion years > according to Wolfram Alpha conversion. That means 1 second == 317.1 year. Looks to me like Star Trek. Its is no wonder why Wolfram calls this Alfa :-) I am waiting for B=E9ta. J=E1nos