[seqfan] Re: 3D version of A000938: 3-in-line inside the nXnXn cube

franktaw at netscape.net franktaw at netscape.net
Sun May 23 09:35:28 CEST 2010


I don't think you really need to say "distinct" after you've said "sets 
of". Sets are by definition collections of distinct objects. Likewise, 
"multisets of" would imply that the objects are not necessarily 
distinct. If it just said "collections of", it would be in need of 
further clarification.

Franklin T. Adams-Watters

-----Original Message-----
From: Ron Hardin <rhhardin at att.net>
To: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu>
Sent: Sat, May 22, 2010 6:50 pm
Subject: [seqfan] Re: 3D version of A000938: 3-in-line inside the nXnXn 
cube


Incidentally the title for A000938

"From the no-3-in-line problem on n X n grid (see references for 
precise
definition)."

could be more informative.

"Sets of 3 collinear points in an nXn grid" seems minimal.

Then misgivings about precision come in

"Sets of 3 distinct collinear points in an nXn grid"

...and so forth

 rhhardin at mindspring.com
rhhardin at att.net (either)




More information about the SeqFan mailing list