obfuscated code deciphered, 2nd time, http://stackoverflow.com/questions/12659951/how-does-this-piece-of-obfuscated-haskell-code-work/12660526#12660526

de-obfuscate.hs

 fix$(<$>)<$>(:)<*>((<$>((:[{- thor's mother -}])<$>))(=<<)<$>(*)<$>(*2))$1

fix $ (<$>) <$> (:) <*>
   (  (<$> ((:[]) <$>) ) (=<<)
--    |----\~~~~~~~~~/-|
      <$>(*)<$>(*2)  
   )
$ 1

fix $ (fmap . (:)) <*>
   (  ((=<<) <$> (fmap (:[])) ) 

      <$>(*)<$>(*2)  
   )
$ 1

fix ( ( (fmap . (:)) <*>
        (  (=<<) . (fmap (:[])) . (*) . (*2) )
      )
        1 )

fmap :: (a->b) -> (r->a) -> (r->b) -- fmap f g x = f (g x) = (f . g) x
<*> :: (r->a->b) -> (r->a) -> (r->b) -- (f<*>g) x = f x (g x)

fix (   (fmap . (:)) 1 
        ( ((=<<) . (fmap (:[])) . (*) . (*2)) 1 ) )

fix (   (fmap (1:))
        (  (=<<) ( (fmap (:[])) ( (*) ( (*2)  1 ) ) ) ) )

fix ( fmap (1:)
        (  (=<<) ( (fmap (:[])) ( (*) 2 ) ) ) )

fix ( fmap (1:)
        (  (=<<) (  fmap (:[])  (2*) ) ) )

fix ( (1:) .
        (  (=<<) ((:[]) . (2*)) ) )

x where x = ( (1:) . ( ((:[]) . (2*)) =<<) ) x

x where x = (1:) (   ( ((:[]) . (2*)) =<<)   x )   -- x :: Num a => [a]

xs where xs = 1 : ( (\x->[2*x]) =<< xs)    -- xs :: Num a => [a]

xs where xs = 1 : map (2*) xs  

---------------------------------
by olsner:

fix$(<$>)<$>(:)<*>((<$>((:[{- Jörð -}])<$>))(=<<)<$>(*)<$>(>>=)(+)($))$1