In May 2010 the man who inspired many to pursue a career in mathematics died aged 92 and that man was Martin Gardner. His columns in Scientific American delighted many and were updated and published in a series of fifteen books. I was delighted to obtain eventually, thanks to Amazon, the complete set. Of course shortly after I’d got the last one the Mathematical Association of America published them all on a searchable CD ROM. Typical!!

So how could I celebrate this man’s life with a puzzle. I thought long and hard about this but there was too much to choose from – pentominoes of course but they’ve been done to death, polyabaloes, polyiamonds perhaps – the list went on and on. I just couldn’t decide and if truth be told I knew that whatever I chose Arden would have made a damned sight better job of it than I would so I opted for the Dedication type puzzle that I’d used to celebrate Euler’s tercentenary. I decided to keep the message very similar but change the second read to dear just to keep solvers on their toes and I felt that Martin Gardner could be described in similar terms.

In Dedication I’d used number definition type clues and it was an easy set taking just a day ( Friday April 13th 2007 to be exact ). As most of my recent puzzles had adopted the number definition type of clue I decided on a change and went for letter/number assignment with all the clues being words having a gardening connection.

Letter/number assignment puzzles are fairly easy to set if you just want to have expressions and not thematic words as the clues and fill the grid in as you go. Here of course I was going to start with a grid already filled in and wanted to use words in the clues which is more challenging. Normally in this sort of puzzle I like to give solvers a hand and use Klan’s hidden location device whereby the grid is numbered but the clues are lettered as this factorises the assignments into three sets. I have used this device in various puzzles in The Magpie whereby I invite solvers to discover some part of my extensive prog rock collection and I wanted to keep it that way. So I needed something else. I recalled a puzzle that had appeared some years previously on Ed Pegg Jnr’s mathpuzzle.com site in which the numbers 1 to 23 had to be ordered in a line such that each of the pairs summed to a perfect square ( this is a nice problem for pupils to have a go at for homework by the way!! ). As I’d managed to find one of the six solutions I decided to use this and mention in the preamble that the order had something to do with perfect squares.

Of course I started off with the grid filled in with a random choice mod 26 for the letters and then barred it off. So only the clues to write and to paraphrase Jeremy Clarkson – “ How hard can it be? “ Well, as Jeremy inevitably finds out, “ Bloody hard! “

I had starting setting this puzzle at the same time as Elementary Number Theory ( June 2010 ) and so alternated between the two but as this puzzle was more difficult I finished off ENT first so I could spend most of the summer holidays on this one.

I studied the entries carefully and of course when you have to come up with the names of flowers etc your mind goes totally blank or mine did anyway. That was where Bradford’s Crossword Lists came in and proved to be invaluable – yes I do own crossword books as well as maths ones!!

I started with 38D and POPPY as it had adjacent letters and would fix P as 3 and using the preamble information O would be 1. So one clue done only forty-nine left to go! Progress was slow and by the end of the school holidays in mid August – remember I live in St Andrews – I had about half the clues done. I managed to catch the odd quarter of an hour here or there over the next few weeks and got some more clues done. I wasn’t particularly bothered as to how difficult the clues would make the solve as solvers had the helpful hint in the preamble about perfect squares – I was just happy that I’d got another clue with a gardening connection! By the end of the October break I only had half a dozen left to do. Then thanks to the snow at the end of November and Fife Council’s policy of bussing kids to a few large secondary schools meant that we were closed for a week and I took the opportunity to write my Christmas cards and finish off the clues. I put the puzzle aside until the Christmas holidays.

The cold solve was easy as I used the preamble information about summing to a perfect square and only needed to solve a few clues. I wrote it up and read it over and immediately knew that this wouldn’t do. It was far too glib and in danger of being rejected which was something I didn’t want given that it was a tribute to a great man notwithstanding the fact that it had taken six months to set!

So I wondered how many letter/number assignments I could get without using the preamble information about perfect squares. I didn’t hold out too much hope but if I could obtain a reasonable number fairly easily then this would be an improvement. So the following day I took advantage of some peace and quiet in that my daughter had gone to visit her boyfriend in the wilds of Aberdeenshire and my wife had taken my son to Dundee for some post Christmas shopping to see how far I could get. Only the cats Tango and Flo would be able to disturb my concentration and as it was snowy outside there was little chance of that! After half an hour I had six letter/number assignments thanks to the factorial and subfactorial parts of clues. Encouraged by this I continued and after a further couple of hours I had all bar five and they gave up their assignments shortly after. Great! I could remove that information about summing to a perfect square from the preamble and say that once completed solvers would have the solution to another puzzle.

Incidentally if you remove 18 from the list you can put the numbers in a loop. If you haven’t read any Martin Gardner books then you should take heed of the message as they are just pure dead brilliant!!

Posted on Thursday, September 1st, 2011 at 3:38 pm under Setting the scene.
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