# [seqfan] Re: What is a "Q unit fraction"?

Neil Sloane njasloane at gmail.com
Sat Dec 22 21:18:07 CET 2018

```I will ask Bob Wilson directly

In the mean time I added "obsc" (to A016013).

Q is pretty certainly a numerical value (or range), since A016017 is
%N A016017 Smallest k such that 1/k can be written as a sum of exactly 2
unit fractions in n ways.
and - also from Bob Wilson  - there is:
%N A018892 Number of ways to write 1/n as a sum of exactly 2 unit fractions.

Best regards
Neil

Neil J. A. Sloane, President, OEIS Foundation.
11 South Adelaide Avenue, Highland Park, NJ 08904, USA.
Also Visiting Scientist, Math. Dept., Rutgers University, Piscataway, NJ.
Email: njasloane at gmail.com

On Sat, Dec 22, 2018 at 2:46 PM Alex Meiburg <timeroot.alex at gmail.com>
wrote:

> Two guesses. First option: this is a "q-analog" of a unit fraction. There
> are "q-analogs" of a variety of quantities, but I don't understand them
> very well and I think you'd have to specify q? Maybe it ends up being
> independent of q here, though.
>
> Second option: you're misparsing the description, and instead of
> decomposing into "Q unit fractions", it's decomposing into plain old unit
> fractions, of which there are Q. Q is some variable that hasn't been
> properly explained.
>
> Actually, I'd bet on the second one, given that they say "exactly Q" unit
> fractions, which really suggests that Q is a quantity of unit fractions.
>
> On Sat, Dec 22, 2018, 11:30 AM Sean A. Irvine <sairvin at gmail.com wrote:
>
> > A016013 Number of ways to write 1/n as a sum of exactly Q unit fractions.
> >
> > Not a lot of information to go on here.
> >
> > Sean.
> >
> > --
> > Seqfan Mailing list - http://list.seqfan.eu/
> >
>
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> Seqfan Mailing list - http://list.seqfan.eu/
>

```