A nice simple one this week!  Which letter comes next in this series?  The answer is neither ‘I’ nor ‘X”.

I, X, X, X, I, X, I, I, I, I, I, I, I, I, I, _

As ever, please do NOT post your answers, but do feel free to say if you think you have solved it and how long it took.  Solution on Monday.

I have produced an ebook containing 101 of the previous Friday Puzzles! It is called PUZZLED and is available for the Kindle (UK here and USA here) and on the iBookstore (UK here in the USA here). You can try 101 of the puzzles for free here.

I’m lost 😦

2. Alex says:

Wow, I actually get to be one of the “less than 10 seconds” internet heroes this week 🙂

1. Rusty says:

Errrrmm. You might want to be careful where you make that boast 😉

3. Got it. Only took one minute

1. Nick Sharrratt says:

4. Given the clue that it’s not ‘I’ or ‘X’, it took about a minute. But, while my answer makes logical sense, and meets the requirements, it is actually wrong in common practice.

1. Michael Sternberg says:

That’s debatable. It’s not much of a practice anymore at all, except, dare I say, for pretentiousness and kitsch. That makes this a more tricky puzzle than it would’ve been a few decades ago.

2. Anonymous says:

3. Based on this comment, I presume we came up with the same answer, because I thought the same thing as soon as I realized what the pattern was.

5. M says:

I think I got it.

thanks for the hint

6. Michael Sternberg says:

5 or 10 minutes, and nothing. Then I guessed an answer on heuristic grounds, but didn’t have a stringent reason. Turns out it was correct. JFGI.

7. Roland says:

Hmm, I’ve got the way of thinking, and I know what Richard thinks should the answer, however in many real-life cases I think the answer may be different from what Richard thinks, as he may have forgotten to check his model of the world with the real world 🙂

1. Ah, good point, I’d forgotten about the ‘special case’ for… y’know… *things*.

Finally, I got it 😉

9. Jack Walton says:

Yes!! Finally got one. Can’t believe its pi…

10. Paul Durrant says:

I can see the answer you’re looking for, but as others have said, it’s wrong. The answer you’re looking for would come after this sequence:

X, I, I, I, I, I, I, I, I, I, I, I, I, _

1. M says:

Or even a shorter sequence. But then nobody would get the answer.

2. Another Richard says:

3. Berhard says:

I think i had a similar idea, but i dont know how long it took, i did not look at the clock…

11. alex says:

I think i have the answer. Took me about a minute, with some wrong possible answers coming to mind first ofcourse!

12. Anders says:

If the answer is what I think it is, then it’s a forgery

13. Guessed at the answer, then took a few minutes working out WHY that was the answer.

I have seen quite a few real-world examples where the answer is not correct, though.

14. ThisIsNotAPseudonym says:

A couple of seconds to work out what sort of letter should be there, a few more seconds to spot the sequence in the first part of the series, but several minutes to realise what the whole sequence represented.

15. Berhard says:

The reason for the non-correct real-world examples reside in the way these elements have been manufactured…with the “uncorrect notation” it is possilbe to use 4 time the same mold/tool to manufacture all of them…

16. mittfh says:

Easy! A few seconds, and even before determining the exact sequence, I had a pretty good idea what the missing letter would be given the requirements. Of course, there are far too many commas in the sequence, but then again removing all the surplus ones would make it even less of a puzzle than it already is 🙂

17. Jag49 says:

Saw it right away

18. Goliath says:

The very first thought was the right one. But spent another two minutes to verify…

19. Chris Emerson says:

Absolutely not a single clue on this one, other than first thinking ‘Roman Numerals’ and having that lead me nowhere

1. Andrew Mitchell says:

Me too. Looking forward to seeing the solution.

2. mittfh says:

Hint: Richard went a bit overboard with his commas…

20. Edgar says:

It took me less than 5 minutes, it was a little tricky. I loved it!

21. Anyone else got Jim Diamond in their heads now?

1. Anders says:

No?

I’m starting to think I have completely misunderstood the puzzle this week, I don’t understand any of the comments

22. Greg23 says:

Very clever clues this week.

23. Got this in seconds, but started reading comments and now I’m worried I dont

24. Weijie says:

I dont see how anyones gets this, im totally confused 😦 i feel dumb now haha

25. Like all these puzzels they require some pre existing knowledge and like crosswords some experience of how Mr. Wiseman’s (sic) mind has wired his brain. Yes, you guessed it I have no idea of any answer. No doubt when the answer is revealed it’ll be like Poirot unmasking the killer – “Well if I’d know that!” Fun nonetheless. I,X,X,X says nothing to my mind & I can’t get Roman Numerals to fit, maybe the commas are equally important. I’ll just wait it out until Monday.

26. Nice one! Took a while but it passed the time. Must be Friday.

27. Yeah I clocked the answer pretty quickly too,

To those who have not seen it, I would not worry, these things are like crosswords, the more of them you do the easier they are, you learn the patterns…in fact something like IQ tests!

Getting it quickly just proves you read things like this blog too much…

I love sci-fi.

29. Jon says:

Took quite a while this week–about seven hours to solve.

30. Guy says:

There’s an alternative answer if the answer was in I’s and X’s but it’s not…C’est la vie

31. Lazy T says:

That’s the sequence of stitches on my operation scar, but I’m no closer to guessing what’s next.
Is it a question mark ?

1. Lazy T says:

ok got it , thanks to the comment about overuse of commas.

32. I had to cheat. Very clever, I’m not sure I would have ever gotten it, although I suppose my guess was correct.

1. Richard Wilkins says:

How did you cheat?

33. Donalbain says:

Curse you commas!

34. Richard Wilkins says:

Ten mins in and I’m still clueless…

35. Tony says:

I have the answer. Took maybe 2 mins. The comments are largely ludicrous I’m afraid. It’s much simpler than people or making out and there is only one possible answer and it does not rely on obscure knowledge. I think some people may have over thunk this one!

1. Anders says:

I don’t believe there is any question in the entire world that has only one possible answer. If you think there is, it is only because you can’t see the others, not because they don’t exist.

Very zen, yes, I know

36. Miggy says:

Posted this on facebook, somebody TOLD ME THE ANSWER and I still don’t get it.

1. Miggy says:

Wow, finally got it. Love it.

37. Mr. D says:

In the end I arrived at an answer that I sort of guessed at originally without really understanding the sequence.

Good puzzle.

38. UXO says:

I suspect this is a puzzle in which the young’uns are SEVERELY hampered. Nice to see there’s SOME mileage in being an old fart…

39. rodney says:

i think i have it. seems easy enough

40. Gerard Engelage says:

In my personal environment here and now it IS an ‘I’, but I’ve seen the answer Richard probably has in mind when visiting London. Or I’m completely on a wrong track after several minutes.