windelicato

case $TERM in
         *xterm*|*rxvt*|(dt|k|E|a)term)
                 preexec () {
                         print -Pn "\e]2;$1\a"    # edited; %n@%m omitted, as I know who and where I am
                 }
                 ;;
 esac

windelicato

factorial ::  Integer -> Integer                                                
factorial n = foldr (*) 1 [1..n]

choose ::  Integer -> Integer -> Integer
choose n k = (factorial n) `div` ((factorial k) * (factorial (n - k)))

main ::  IO ()
main = print $ choose 40 20