[seqfan] Re: Announcements: faster search, new Sys Admin

[M. F. Hasler]

On Sun, Jun 23, 2019 at 5:19 PM Russ Cox <rsc at swtch.com> wrote:

> (...)

As part of this, I have been looking at actual searches, and I've noticed
> that there is a steady stream of people searching for space-separated
> number lists like:
>     1 2 3 6 11 23 47 106 235
>     "1 2 3 6 11 23 47 106 235"

(...)

As an experiment, I've changed the rules on the server to turn three or
> more space-separated numbers into a sequence search (...)


Hello Russ et al,

My attention was drawn on the fact that this "recent" change of converting
"x y z ..."  to "x, y, z, ..." instead of "subseq: x, y, z..." as earlier,
is only done when x y z... contain only digits (but no minus sign !).
In other words, a search for "-x -y -z ..." is the same as was "x y z"
before (and approximately but not exactly the same as "subseq:x, y, z").

That may actually be handy (because I found the distinction between "x y z"
and "x,y,z" useful)
but I'm not sure it is intentional.

- Maximilian


> My guess is that these searches intend to search for that exact sequence
> (this being the Online Encyclopedia of Integer SEQUENCES and all),
> and that despite the hints and warnings about using comma syntax
> instead, many people don't realize what is going on.
>
> As an experiment, I've changed the rules on the server to turn three
> or more space-separated numbers into a sequence search, as if they'd
> been comma-separated. So now these are all the same search:
>
>     1,2,3,6,11,23,47,106,235
>     1 2 3 6 11 23 47 106 235
>     "1 2 3 6 11 23 47 106 235"
>
> To search for those numbers appearing all together in a sequence entry
> but not necessarily in order, they can be quoted individually, as in
> ["1" "2" "3" "6" "11" "23" "47" "106" "235"]. And of course if the order
> is known but not where index gaps are, there are always subsequence
> searches like:
>
>     subseq:2,6,47,106
>     2,3,6,__,235
>
> The hints page https://oeis.org/hints.html is updated with the new
> state of the world.
>
> Please let me know if you think the new behavior is problematic or
> can be improved.
>
> Best,
> Russ
>
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>