I'm trying to calculate

Sum[(1/n)^(n), {n, 1, Infinity}]

But mathematica outputs the input directly. What is the problem? when I put the same expression into wolframalpha, it gives me the answer but not mathematica.

  • 2
    $\begingroup$ Use NSum in Mathematica to get a numerical approximation. $\endgroup$ Nov 6, 2021 at 15:09

1 Answer 1


Mathematica Sum just returns input means MMA doesn't find an analytical answer

The sum seems to be convergent

SumConvergence[(1/n)^(n), n]
(* True *) 

Numerically result

NSum[(1/n)^(n), {n, 1, Infinity}]

That's the result from WolframAlpha!


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