**Paste:**#107536**Author(s):**1HaskellADay**Language:**Haskell**Channel:**-**Created:**2014-07-15 11:59:53 UTC

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 | {-- Primes, and ... 'not primes' Question: what is the opposite of 'prime,' as in 'prime numbers'? 'Plain' numbers? 'Secondary' numbers? Anyway. I read on the internet, so it must be true, that for every prime number, p, there follows sometime after it a run of at least p-consecutive numbers that are not prime. So: 2 has [8, 9] 3 has [8, 9, 10] 5 has [720, 721, 722, 723, 724] ... That last one was a big hint (and there is always the 'internets'). Write a function: --} plainRun :: Integer -> [Integer] plainRun prime = undefined {-- such that for a prime number, prime, it returns a list of not-prime consecutive numbers of length prime. This exercise was inspired by the tweet from @AlgebraFact: "For every n, you can find a span of n consecutive numbers containing no primes." tweeted on July 8th, 2014 --} |