> let f b = if b <= 1 then 0 else 2 + f (b`div`2) + f (b-1)
> map (i -> (i, f i)) [0..10]
[(0,0), (1,0), (2,2), (3,4), (4,8), (5,12), (6,18), (7,24), (8,34), (9,44), (10,58)]