Max GCD Permutation Product

Leroy Quet qq-quet at mindspring.com
Fri Feb 6 00:45:17 CET 2004


David Wasserman's reply in "Max GCD Permutation Product":
>The two sequences first disagree at m = 14.

got me wondering (actually I wondered about this earlier) about sequences 
in the EIS which match every term stored in the database, but are unequal 
ultimately at higher-indexed terms.

We can have 3 situations with these false matches:

1) the 2 sequences are known to be different, and a comment about this 
fact is mentioned on the sequences' EIS web-page.

2) the sequences are either just assumed wrongly to be identitical by the 
contributers to the      sequences' (common) web-page, or none of the 
contributers have bothered to include in the database that the sequences 
differ ultimately. 

3) it is not known with certainty what the situation is regarding the 
sequences being the same or differing. (and this uncertainty is mentioned 
in the EIS )  
 
   
(And, of course, perhaps a contributer assumed, using faulty mathematics, 
that the sequences differed, which happens to be correct anyway.)


Or a single sequence can be falsely assumed to be 2 or more different 
sequences as well.


Are these situations above common in the EIS? I cannot recall any 
specific example of either. 
But each  of the above situations must occur at a significant rate, given 
how many sequences are now in the database.

For fun, I ask here for interesting examples of the  above situations.

And more seriously, I post this email as a warning for all of us when 
making assumptions regarding sequences' sameness.

Actually, as far as the (now only finite-sized) EIS is concerned, are 2 
sequences that have the same terms as far as the EIS database is 
concerned, but differ at higher index(es),    considered officially to be 
the "same" sequence or different  sequences?

thanks,
Leroy Quet





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