Interrelationship between power of 2 and integer length

  • Context: Undergrad 
  • Thread starter Thread starter Nile3
  • Start date Start date
  • Tags Tags
    Integer Length Power
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
3 replies · 2K views
Nile3
Messages
42
Reaction score
0
Hello, I was wondering if someone knew the equation which describe the exact or statistical relation between the length(# of digits) of a power of 2 based on it's power.

I plotted 200 of the powers in mathematica and I get a fairly straightforward staircase plot. I'm just wondering what's the rule here.

4.jpg
 
Mathematics news on Phys.org
The length of an integer ##x## in basis 10 is given by ##\lfloor\log_{10}(x)\rfloor+1##, where the strange brackets denote the largest integer smaller or equal than ##x##. So if ##x=2^n##, then the length is

[tex]\lfloor \log_{10}(2^n)\rfloor + 1 \sim n\log_{10}(2) + 1[/tex]
 
  • Like
Likes   Reactions: 1 person
If the number of digits of a number increases linearly, the number increases exponentially; if the exponent of a number increases linearly, the number increases exponentially. Basically you've plotted the implicit function 10^y = 2^x.

y/x = b is a constant because the equation 2 = 10^b has one root. To estimate b consider 2^10 = 1024 and 10^3 = 1000.
 
Last edited:
n * (memorize 0.3 as log[10,2]) +1, excellent, thanks!