# [seqfan] Re: A Sequential Puzzle

Olivier Gerard olivier.gerard at gmail.com
Sun Mar 25 03:26:47 CEST 2018

```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/
>
```