Talk:Truncatable primes

Is Zero allowed?

I think the task should explicitly state whether zero is allowed in the numbers or not. If allowed then 999907 is the largest left-truncatable prime less than 1000000. --Tikkanz 00:58, 9 September 2010 (UTC)

Thanks Tikkanz. I've disallowed zero as this is done in part of the Mathworld article. It means disallowing '07' as being a prime for example, and seems reasonable. --Paddy3118 03:27, 9 September 2010 (UTC)

OEIS

For reference, a few of the related OEIS sequences are A024770 (right) and A024785 (left).

Phantom Category

I was trying to test cleaning up some categories of tasks (see Rosetta_Code:Village_Pump/Grouping_tasks) and thought I'd start with Primes, Prime, and Prime Numbers. So I added Category:Prime Numbers but low and behold I can't find where Truncatable_primes references Primes. In the html source there is a "wgCategories=[" inside a script and I can see at the bottom where a "Category:Primes (page does not exist)" is generated but I can't find where to fix this. Help? --Dgamey 10:29, 18 May 2011 (UTC)

Perhaps in the Clojure entry? --Rdm 11:11, 18 May 2011 (UTC)

Ah ha. Not Clojure, Haskell references a library called Primes. That has to be the wrong way to do it! It would create dozens of phantom categories all over RC. It has to be a primes member or package in some Haskell library. Is there a haskell user that can fix this out there? --Dgamey 11:26, 18 May 2011 (UTC)

If that's the real name for the library then that is the right way to do it. It may need to change to something like {{libheader|Primes (Haskell)}}. --Mwn3d 12:22, 18 May 2011 (UTC)

redefinition of truncatable primes

I think this task's definition of truncatable primes needs to be redefined to include the phrase base ten. It could be something like:

A truncatable prime (expressed in base ten) is a prime that when successive digits are removed from one end of the prime, all numbers thus found are prime.

or some such wording.
As an alternative, could MathWorld™'s definition be used? -- Gerard Schildberger 16:17, 12 September 2012 (UTC)