GCHQ puzzle

[gasman]

Got through to section 5 after finally working out 4b. OMG I have spent so many hours on this thing. Section 5 is on another level though. I don't understand at least half of those. Had been interesting g though. Dying to see how many people do solve it all

 

[Sporky McGuffin]

Gizza vague clue for 4B mister!

 

[gasman]

I wasn't a million miles away looking at them as sums of different exponentials of small primes
However, each of the numbers is the sum of 3 progressions small numbers (i.e. not necessarily primes) and one of them is a progression which goes from negative to positive - hence the 3 negative numbers to start with

 

[Sporky McGuffin]

Ah - I'd been thinking sum of 5 consecutives but hadn't achieved much traction on it. Thanks - I will press on.

 

[Steve Maskery]

I know I started all this, but I have to say I am impressed with your tenacity, guys, I gave up ages ago. I was glad just to have done the first couple of pages.