[seqfan] Re: Question regarding A073216

D. S. McNeil dsm054 at gmail.com
Sat Oct 8 18:19:46 CEST 2011


> 1, 2, 3, 5, 6, 9, 14, 15, 18, 27, 41, 42, 45, 54, 81.

[...]

> Question: Assuming the sequence given in the paper is indeed identical to
> A073216 (to be confirmed)

I think they're the same.  The paper sequence is defined as integers
of the form c/2 where c has the sum of its base 3 digits being 2, so
it's the sum of two powers of 3 divided by 2 (either distinct powers,
looking like 1000100, or nondistinct, like 2000), which is A073216.

> is it legitimate to include a link to the paper in
> the OEIS entry for the sequence?

Definitely.  Please submit it.  We could probably do with a lot more
references like this and a lot fewer random walks in symbolic
expression space..

> PS
> I notice A055235 is marked 'base' - is this right?

I would say no, and would approve the removal, but this shows why base
is such a troublesome keyword:
"sum of two powers of three", to which I wouldn't give the base
keyword, is exactly equivalent to "has base 3 digitsum of 2", to which
I would.  Since OEIS entries are sequence-centred and not
definition-centred, this is a problem.


Doug



More information about the SeqFan mailing list