[seqfan] Re: Definition of A141534

franktaw at netscape.net franktaw at netscape.net
Sun Jun 5 17:33:10 CEST 2011

I don't think the sequence is in error, though I would like to see a 
better definition.

The word "centered" is perhaps the key. The pentagonal numbers in the 
sum appear to be the centered pentagonal numbers 
http://oeis.org/A005891. Exactly how this continues for later values 
(i.e., what kind of hexagonal values, etc., are being used) is not 
clear to me.

What is needed is a sequence with the array of which this is the 
antidiagonal sums, and an appropriate definition there; plus 
cross-refs, of course.

Franklin T. Adams-Watters

-----Original Message-----
From: Richard Mathar <mathar at strw.leidenuniv.nl>

Sequence http://oeis.org/A141534 is defined (apparently) as some simple
sums of the array of polygonal numbers A086270, and one would expect
this to match A006522 from A006522(3) on. The terms, however, fit a 
formula, and I have not been able to resolve this matter.

Does someone have an idea how the actual entries could match something
defined in terms of sums of polygonal numbers?
Currently this looks to me like a numerical error by the author.

The option to resolve this are:
i) mark the sequence as obsc and leave as is (a tutorial of 
ii) delete
iii) redefine as the 4th order matching polynomial
iv) Copy over terms A006522(3,4,5,6...) to match the definition.

Richard Mathar

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