Visualize the parity of the sum of digits from numbers of the Fibonacci sequence. https://oeis.org/A004090

sumfibparity.hs

import Data.Char (digitToInt)
import System.IO

main :: IO ()
main = do
    hSetBuffering stdout NoBuffering
    putStrLn $ concatMap toFancy $ sumOfDigits fib

toFancy :: Integer -> String
toFancy x
    | even x = "▓"
    | otherwise = "░"

sumOfDigits :: [Integer] -> [Integer]
sumOfDigits = map (sum . map (toInteger . digitToInt) . show)

fib :: [Integer]
fib = 0 : 1 : zipWith (+) fib (tail fib)

take 50 $ sumOfDigits fib
[0,1,1,2,3,5,8,4,3,7,10,17,9,8,17,7,24,22,19,14,24,20,17,28,27,19,19,29,21,23,17,31,30,34,37,35,27,35,44,43,24,31,46,41,33,29,35,37,54,55]

putStrLn $ concatMap toFancy it
▓░░▓░░▓▓░░▓░░▓░░▓▓░▓▓▓░▓░░░░░░░░▓▓░░░░▓░▓░▓░░░░░▓░