[seqfan] Re: near duplicates A132209 and A142463

franktaw at netscape.net franktaw at netscape.net
Fri Nov 13 23:26:01 CET 2009


I'm OK with these staying separate.  But there are several problems 
with A132209:

(1) The name.  The sequence doesn't "allow us to find the X values" for 
2X^3 + 3X^2 = Y^2; it IS the X values.  (This unfortunate phrasing 
seems to be repeated in a number of other sequences.  Sigh.)
(2) The formula 2*n^2 + 6n + 3 is off by 1; it should be 2n^2 + 2n - 1. 
 Likewise, the formula for the Y values should be (2n^2 + 2n - 1)(2n-1).
(3) The comment from Vincenzo Librandi doesn't belong here.  
Essentially the same comment is in A142463, which is where it belongs.

And, of course, if both are kept, they should reference each other 
("essentially the same as ...").

Franklin T. Adams-Watters

-----Original Message-----
From: Max Alekseyev <maxale at gmail.com>

A132209 and A142463 are the same except of the first term. In both
cases the first terms seems to be rather out of the context and can be
eliminated by restricting sequence to positive elements or shifting
the offset by 1.
Should these two sequences be merged?
Max




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