Problem 146

http://projecteuler.net/index.php?section=problems&id=146

import Number
import Data.List
import Control.Monad
step = [1,3,7,9,13,27]
indivisible p n = and [mod (n*n+s) p /=  | s <-step]
residue u  p = [n | n <-[..min u (p-1)], indivisible p n]
residues u [p] = residue u p
residues u (p:ps) = [k*q+n | n <-residues u ps, k <-[..min (p-1) $ div (u-n) q], indivisible p $ mod (k*q+n) p]
where q = product ps
nextPrime p = head.filter isPrime' $[p+1..]
isConsPrimes (p:ps) = isPrime' p && (and.zipWith (==) ps .map nextPrime) (p:ps)
isPrimePattern n = isConsPrimes.map (+n*n)$step
p146 n = [m | m <- residues n smallPrimes, isPrimePattern m]
where smallPrimes = reverse.takeWhile(<100)$primes
main = print.sum.p146$150*10^6
More Reading
Newer// 150問
Older// Problem 148