Summation of 1^1+2^2+3^3+....+k^k

  • Context: Undergrad 
  • Thread starter Thread starter ddddd28
  • Start date Start date
  • Tags Tags
    summation
Click For Summary

Discussion Overview

The discussion revolves around the summation of the series \( \sum_{n=1}^{k} n^n \) and whether it can be represented in a shorter form. Participants explore potential mathematical representations and approximations, including references to known formulas and techniques.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions if there is a shorter representation for the summation \( \sum_{n=1}^{k} n^n \) and notes it does not fit the form of constant power series.
  • Another participant points out a potential confusion in the notation, asking whether the discussion is about \( n^n \) or \( n^2 \).
  • A participant suggests that while there may not be an analytic expression for \( n^n \), it could be approximated using the Stirling formula and integration.
  • One participant proposes using Faulhaber's formula to express \( n^n \) in terms of Bernoulli numbers, but expresses skepticism about finding a shorter representation.
  • Another participant counters that for engineers, particularly for larger values of \( k \), the expression may not be as lengthy or complex as suggested.
  • There is a reiteration of the idea that mathematicians might find ways to shorten the expression, implying differing perspectives on the complexity of the summation.

Areas of Agreement / Disagreement

Participants express differing views on the possibility of shortening the summation representation, with some suggesting it is unlikely while others argue it may be feasible under certain conditions. No consensus is reached on the matter.

Contextual Notes

Participants reference various mathematical techniques and formulas, but the discussion remains open-ended regarding the assumptions and limitations of these approaches.

ddddd28
Messages
73
Reaction score
4
Does that summatiom have a shorter representation at all?
##\sum_{n=1}^{k} n^n = ?##
I guess it is not of the form of constant power series, but I could not find an alternative.

Mentor note: made formula render properly[/size]
 
Last edited by a moderator:
Mathematics news on Phys.org
Huh? Looks both like nn to me.

I'm not aware of an analytic expression. It can probably be approximated with the Stirling formula and then some integration.
 
  • Like
Likes   Reactions: fresh_42
It's kk :-)
 
Maybe one can use Faulhaber to rewrite ##n^n## as difference of ##\sum_{k=1}^n k^n - \sum_{k=1}^{n-1} k^n## to get an expression in Bernoulli numbers which can then be summed again. A giant polynomial of Bernoulli numbers. Of course my bet to the original question
ddddd28 said:
Does that summatiom have a shorter representation at all?
is NO. I mean the length of the expression is seven! Almost impossible to shorten.
 
fresh_42 said:
is NO. I mean the length of the expression is seven! Almost impossible to shorten.
Not true for an engineer for k>5 or so...

k^k
 
  • Like
Likes   Reactions: fresh_42
berkeman said:
Not true for an engineer for k>5 or so...

k^k
Now as you say it. Mathematicians can also shorter ...
##O(1)##
 
  • Like
Likes   Reactions: berkeman

Similar threads

  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 16 ·
Replies
16
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 6 ·
Replies
6
Views
2K