# [seqfan] Re: A Sequential Puzzle

Neil Sloane njasloane at gmail.com
Sun Mar 25 04:26:16 CEST 2018

```As long as that sequence is a sequence of rationals, it should
be added to the OEIS as a pair of linked sequences (nums and denoms).

This has always been sufficient reason to add a seq to the OEIS, that it
appeared on a quiz.

I've always hated those tests, and have enjoyed getting emails from the
people
who complain when I've added their test sequences to the OEIS. In the other
direction, I've often
noticed sequences taken from the OEIS appearing on these tests.  So it
averages out.

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, Mar 24, 2018 at 9:26 PM, Olivier Gerard <olivier.gerard at gmail.com>
wrote:

> A possible answer for q is 499/6 = 83+1/6
>
> This is a value you obtain if you consider the list as the values of the
> polynomial
> of smallest degree interpolating    35,45, 60, q, 120,180,280, 450 and 744
> for x = 1,2, ... 9
> and solving for q so that it matches 1260 for x=10.
>
> This is, in fact, the value making all the 9 successive differences of the
> sequence
> positive.
>
> As q is rational, it would explain why it is not in the OEIS.
>
>
> The smallest 10th term >= 1260 for which q is integer is 1274, giving q =
> 83.
>
>
>
>
> On Sat, Mar 24, 2018 at 5:21 PM, <charliemath at optonline.net> wrote:
>
> > Some SeqFans may already be acquainted with a weekly column  entitled
> > Varsity Math, published Saturdays in the Wall St. Journal's Review
> section.
> >
> >
> > The second ot two problems in today's edition is called The Missing
> > Element and reads as follows:
> >
> >
> > The open-ended sequence ...35,45, 60, q, 120,180,280, 450, 744, 1260,...
> > has an undisclosed element, q.  Find a simple continuous function to
> > generate the sequence and compute the surprise answer for q.
> >
> >
> > I did a search for any sequence that contains 35 45 60 120 180 280 450
> 744
> > 1260.
> > Seqence A103252 contains each value except 744.  No sequence contains all
> > 9 values.
> >
> >
> > I'm guessing this sequence, once found, will make its way into OEIS.
> >
> >
> > Enjoy!
> >
> >
> > Charlie Marion
> >
> > --
> > Seqfan Mailing list - http://list.seqfan.eu/
> >
>
> --
> Seqfan Mailing list - http://list.seqfan.eu/
>
```