37 lines
833 B
Haskell
37 lines
833 B
Haskell
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import Data.List
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divisor_count :: Integer -> Int
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divisor_count n = length [x | x <- [1..n], rem n x == 0]
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--triangles :: [Integer]
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--triangles = undefined
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triag :: [Integer]
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triag = triag' 1 2
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where triag' s i = s:(triag' (s+i) (i+1))
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rest60 :: Integer -> Integer
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rest60 x = rem x 60
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atkin :: Int -> [Integer]
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atkin = undefined
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prims :: Integer -> [Integer]
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prims n = eres [2..n]
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where
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eres (x:xs)
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| x*x > n = (x:xs)
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| otherwise = x:eres (filter (\y -> rem y x /= 0) xs)
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prim_factors :: Integer -> [Integer]
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prim_factors 1 = []
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prim_factors x = p:prim_factors (quot x p)
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where p = head $ filter (\y -> rem x y == 0) (prims x)
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--divisor_count' :: Integer -> Int
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divisor_count' x = product . map (succ . length) . group $ prim_factors x
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main = do
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putStrLn . show $ filter (\x -> divisor_count' x >= 500) triag
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