request: ^ and constant searching

[Alonso Del Arte]

> (1) The ability to search for sequences starting with a given term, e.g.,
> "^2,3,4,5,6,7,8,9" finds only sequences whose initial term is 2 (this
> would be very handy for locating similar sequences that differ only in the
> first term or two, a process that is otherwise quite painful as far as
> I've been able to tell)
>

I've sometimes thought of a similar feature: being able to find, for
example, which sequences have a(3) = 2 and a(5) = 4. This would be
nice for certain problems where it's easy to calculate two
non-consecutive terms but one particular term is spectacularly large,
so you have something like 2, 3, ??????, 5, 7. I have no idea how this
search feature could be implemented, though.

Alonso