What Is the Exact Value of the Infinite Series Sum of n^-n?

  • Thread starter Thread starter Swimmingly!
  • Start date Start date
  • Tags Tags
    Sum
Click For Summary
SUMMARY

The infinite series sum of n^-n, denoted as L, converges to approximately 1.291286, as confirmed by Wolfram Alpha. The series is bounded between 0 and 1.5, indicating a definitive value exists within this range. Various methods to derive L, including integration and Taylor expansions, have proven ineffective, highlighting the complexity of the series and its relationship to known constants.

PREREQUISITES
  • Understanding of infinite series and convergence concepts.
  • Familiarity with exponential functions and logarithms.
  • Basic knowledge of Taylor series and their applications.
  • Experience with mathematical software tools like Wolfram Alpha.
NEXT STEPS
  • Research the convergence properties of infinite series.
  • Explore advanced techniques in Taylor series expansions.
  • Investigate the relationship between exponential functions and logarithmic identities.
  • Examine existing literature on the sum of n^-n and related mathematical constants.
USEFUL FOR

Mathematicians, students studying advanced calculus, and anyone interested in the properties of infinite series and their convergence.

Swimmingly!
Messages
43
Reaction score
0

Homework Statement


http://latex.codecogs.com/examples/00a93bb6c6c645f9802b88f4c1c986fc.gif
Let's call this L.
Find the exact value of L.

Homework Equations


http://latex.codecogs.com/examples/6835d744da9ce19b352158cd01b91e91.gif
1+1/2=1,5

The Attempt at a Solution


  • L>0.
  • 1,5>L
  • The function is always growing
Therefore there must be an definite answer in ]1,5 ; 0[
Wolfram gives 1,291286...Spam of possible methods:
-Trying to find the value relating it to integration. Impossible. The integral is not defined.
-Try to find an adequate Taylor Expansion. Can't find a function that fits AND I don't know any pretty method to relation expansions to functions.
-Try to find a relatable sum such as that of the differences or quocients of the next term. Couldn't do much with it.
-Use n^-n=e^ln(n^-n)=e^(-n*ln n). Can't do much with it.
-Turn into a product problem n^-n=ln(e^(n^-n)). Can't do much with it.
-Use a general formula for the sum of a^(k) to infinity. Haven't tried but it doesn't seem to simplify.Main question:
Is it representable using already known constants?
 
Last edited by a moderator:
Physics news on Phys.org

Similar threads

  • · Replies 14 ·
Replies
14
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 2 ·
Replies
2
Views
4K
Replies
4
Views
2K
Replies
3
Views
1K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
8
Views
2K
  • · Replies 22 ·
Replies
22
Views
4K
  • · Replies 1 ·
Replies
1
Views
2K