Listener 4010: Euclid's Algorithm by Aedites

[midazolam]

Here is the link to the numerical listener crossword

[kayakamina]

Thanks for the link.

[AHearer]

Thanks for the link. Can't say I'm looking forward to this.

[Deviant]

Thanks. This must set a record for the most clues ever in a standard Listener crossword. I do so love the mathematicals - it's going to take me a day to understand how to tackle this one - or to write a computer program to do it for me :)

[cluelessJoe]

Thanks M ... at first glance, it looks as though you might have just tied me up for the next ten days or so!

[Spaghetti]

Good luck to you all! I never bother with ones involving numbers, odd shapes or Playfair codes!

[bobbycollins]

See you all next week, chaps

[mad max]

Think I will have another go at last weeks

[bobbycollins]

Sorry to butt in again, but may I recommend this week's "Spectator" puzzle (available free on-line) to non-sums puzzlers?

I really enjoyed it, and it was quite tricky to get going.

[Cruncher]

Eek....!!!

[midazolam]

i think we are in for the long haul

after all this time only one cell filled in. Not sure whether this might come in handy later but here is a euclidean calculator

http://home.att.net/~srschmitt/script_euclid.h tml

[lordbadger]

zzzzzzzzzzzzzzz

for anyone who is daunted by this tedious offering, and/or irritated by it spoiling your run of correct solutions to proper crosswords (!), it is actually pretty straightforward once you do the obvious (?) initial transformation

[AHearer]

Thanks, bobbycollins, for suggesting the Spectator. I enjoyed it, but now I'm back to this one with no progress so far.

[MartianAlien]

Thanks lordbadger but your comments are totally unhelpful.
1 F has 5 different common factors - ie all intercepts given
2 C has no common factors - ie no intercepts
3 "i" and "j" never appear in clues
Is any of this relevant?

By the way, these mathematical entries really are irrelevant as CROSSWORDs. Why must we suffer them!

[dix-dixie]

Hi !
Can anyone shed some light...Should the first sentence of the instructions for this crossword actually read "whose PRIME factors are restricted to.." - otherwise it doesn't make sense? Or am i missing something obvious? Cheers!!

[AHearer]

Yes, dix-dixie, your interpretation is correct: every entry is the product of a number of distinct primes in the given range. It does come out in the end, but this was one of my more intense, and less enjoyable, Saturdays. Thank goodness there's only one of these a quarter.

[beermagnet]

Ah, we were put on this earth to suffer - hang on, maybe you weren't MartianAlien!
I agree LordB's comments were unnecessarily negative. Some of us enjoy tedious numberwork (here speaks someone with a better hit rate on the numericals than the others) - but I know what he means - once the numbers start going in, the thing will be finished if you are careful: I scribbled a 37 instead of 47 at one point (or some such) which threw out the next few calculations. If I hadn't noticed as soon as I did, I may have had real trouble backtracking, I might've lost the will to continue.
It is one of those where getting started is the main hurdle. I had the same experience as Midaz. - couple of hours before I put the first definite digit in the grid. Then I took a break and came back to it fresh.
I didn't use any Euclidean calculator but a spreadsheet took a bit of hammering.
Martian, your 3 observations are not particularly relevant.
1 & 2. F's glut and C's dearth of intercept factors is by chance - I didn't take any note of it.
3. Missing "i": There are 22 primes between 2 and 79 inclusive - they are indicated by lowercase a through w though it is not just i that is not mentioned j,o and q aren't in any clue either.
There is nothing to say all 22 are used and even if they are used they might never be in an entry that intercepts with another that uses it.
I approached it by listing all the prime factor letters for each "spoke" and "circular" entry that we know of from the clues. Then thought about those with the most factors, especially where they intercept another with a lot of factors.
Anyway glad I got there in the end as I just ran out of beer.
Pip pip!

[MartianAlien]

Thanks beermagnet
I have already filled a grid with the prime factor letters, but was concerned that L appeared so often and not "i". [Lower case is potentially a problem.]
The region of radials 29 to 32 appear to be the starting point, but I have yet to enter a single digit.
The first won't be 1 digit but a 5-digit entry, presumably.
I have not given up yet - it's more like soduku than a crossword.

[midazolam]

try 17-20 as a better starting block

[lordbadger]

Aha yes indeed .. "more like a sudoku" .. enough said ..

Beermagnet described the easiest way of getting going, i.e. transform the clues into 1-40, and A-Z, each as a product of lower case letters. Then you can start making some deductions. The entries with most factors would be a good place to start.

I think, MartianAlien, my first entry/entries WERE a single digit actually.

[Clamzy]

My first entry was also a single digit at the end of Y.
Has anyone else noticed that there's no f in Z?
I'll get my coat:-)