Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: Richard Heathfield <rjh@cpax.org.uk>
Newsgroups: rec.puzzles
Subject: Re: GCHQ Monday Puzzle
Date: Tue, 6 May 2025 07:36:14 +0100
Organization: Fix this later
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On 06/05/2025 07:02, David Entwistle wrote:
> On Mon, 10 Feb 2025 08:59:23 -0000 (UTC), David Entwistle wrote:
> 
>> I'm sure many of you know that GCHQ publish a puzzle each Monday on
>> their X account. For any that don't:
>>
>> https://x.com/GCHQ
> 
> There's been no GCHQ Puzzle this week - Monday was a bank holiday in the
> UK. This one is from the excellent GCHQ Puzzle Book 1.
> 
> 125. Number Sequence IV
> (a) 7, 8, 5, 5, 3, 4, 4, ?
> (b) 2, 2, 2, 3, 2, 2, 4, 2, 3, ?
> (c) 1, 2, 3, 2, 1, 2, 3, 4, 2, 1, 2, 3, 4, 3, 2, ?
> 
> I think I know (a) and (c), but not (b), as yet.

You do know (a). Even /I/ know (a).

You may well know (c), although I can't see it myself.

(b), however, is just one of their 'read my mind' puzzles that 
they love to waste people's time with. A good cryptographer tries 
not to leave any hooks you can pick at. A good puzzle setter 
tries to be fair to the solver by leaving at least /one/ hook. 
GCHQ is packed full of good cryptographers.

-- 
Richard Heathfield
Email: rjh at cpax dot org dot uk
"Usenet is a strange place" - dmr 29 July 1999
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