The number of binary bits necessary to represent a number, given explicitly by
| 
(1)
 | |||
| 
(2)
 | 
where  is the ceiling
 function, 
 is the floor function, and 
 is lg, the logarithm
 to base 2. For 
,
 1, 2, ..., the sequence of bit lengths is given by 0, 1, 2, 2, 3, 3, 3, 3, 4, 4,
 4, 4, 4, 4, 4, 4, 5, 5, ... (OEIS A029837).
 The function is given by the Wolfram Language
 function BitLength[n].
 
 
         
	    
	
    

