@Rouben Rostamian  When n=4 and j=16 then the compiled code tries to compute (15!)^2 which is too big for a 64bit integer in compiled C, and it throws that error.

So one might ask: how to compute ((j-1)!)^2 mod j without having to actually compute ((j-1)!)^2 explicitly.  Handling only the square (via inert `mod` stuff`) is not enough to go much further; the factorial is a sticky wicket.

@ecterrab If I run the same worksheet as I did before, using Maple 2024.1, then some of those diff calls take a while, and then throw an error.

So there was certainly some point release at which it did not work ok in Maple 2024.

I mention all this so that the OP of this Question understands that loading the Physics package can indeed make a difference here.

I leave it to the OP to decide whether to go with Maple 2024.2, or not load Physics, or install the latest add-on Physics update package, etc.

Download why_ac_M2024.1_oops.mw

@salim-barzani It works ok in my Maple 2024.1 without Physics loaded.

Download why_ac_M2024.1.mw

@nm I suggest using Grid instead of Threads for dsolve computations that you want to run in parallel.

What happens if you omit the with(Physics) line?

The limit and int commands are not Thread-safe, in general, and neither is dsolve.

May I ask, did you file a Software Change Request (ie. bug report) against this, either by form, direct message to Tech Support, or via the Beta forum?

@mmcdara Note that this member has deleted their own earlier Questions, several times, including earlier Question threads that have involved responses.

This member asked whether they ought to delete their own earlier Questions, prior to posting related followup queries. I responded, no, please don't do that; It makes no sense to remove the earlier context, and doing so would be unhelpful. I suggested instead to retain all the earlier details & responses, and either put the followup details/queries in new Replies on the earlier threads, or Branch off earlier threads. That was repeating similar requests made half a dozen times before. In direct response, this member then responded that yes, they'd do that.

The member then admitted to deleting yet more earlier Question material (thread, and responses) of their own. So now it's much harder for any moderator to know whether followup Questions by them are duplicates.

I shall steer clear of all Questions by this member.

ps. Not everyone may have seen the full extent of multiple-posting/reposting by this member (some may get deleted before being seen by all, etc) -- possibly the most extreme I've seen in over 20 years on this site.

Are you asking about Maple Flow, or Maple?

@salim-barzani I suppose that it may be important to some members to know that you might delete your own Question threads, even after they have responded.

@Carl Love I have a hazy recollection that double-quote strings were already in MapleV R5.

@romanrieme You can index into a VectorCalculus Vector in the usual ways, using square brackets.

You can access the value. You can assign it to some other name. You can replace the element's value. And so on.

Download VC_Vector_indexing.mw

Did you delete any of your own previous Question thread on ODEs?

I mean, the threads on Hirota Bilinear Form? Did you yourself delete any of those?

Do you have a question to accompany that expression?

ps. I've deleted the three other duplicate postings of your expression.

@salim-barzani You could always try (re)reading the User Guide, and its sections on input.

There's a section there on 1-D Math Input, btw.