Evaluate $sum_{k=1}^infty e^{-sqrt{2 pi k}}$












1












$begingroup$


Is there a closed form of this series
$$sum_{k=1}^infty e^{-sqrt{2 pi k}} $$
It can help to solve a very hard integral problem
$int_0^infty e^{-x}x sin(x)coth(x^2) .dx$










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$endgroup$








  • 2




    $begingroup$
    What is that hard integral? Don't keep it for yourself please :D
    $endgroup$
    – Zacky
    Dec 18 '18 at 21:00










  • $begingroup$
    No closed form as per Wolfram Alpha. How did that sum arise ? What's the integral ?
    $endgroup$
    – Rebellos
    Dec 18 '18 at 21:04












  • $begingroup$
    Check it now it's edited
    $endgroup$
    – Ahmad Albaw
    Dec 18 '18 at 21:11










  • $begingroup$
    Sorry. Unsolvable........
    $endgroup$
    – Mostafa Ayaz
    Jan 5 at 7:20
















1












$begingroup$


Is there a closed form of this series
$$sum_{k=1}^infty e^{-sqrt{2 pi k}} $$
It can help to solve a very hard integral problem
$int_0^infty e^{-x}x sin(x)coth(x^2) .dx$










share|cite|improve this question











$endgroup$








  • 2




    $begingroup$
    What is that hard integral? Don't keep it for yourself please :D
    $endgroup$
    – Zacky
    Dec 18 '18 at 21:00










  • $begingroup$
    No closed form as per Wolfram Alpha. How did that sum arise ? What's the integral ?
    $endgroup$
    – Rebellos
    Dec 18 '18 at 21:04












  • $begingroup$
    Check it now it's edited
    $endgroup$
    – Ahmad Albaw
    Dec 18 '18 at 21:11










  • $begingroup$
    Sorry. Unsolvable........
    $endgroup$
    – Mostafa Ayaz
    Jan 5 at 7:20














1












1








1


1



$begingroup$


Is there a closed form of this series
$$sum_{k=1}^infty e^{-sqrt{2 pi k}} $$
It can help to solve a very hard integral problem
$int_0^infty e^{-x}x sin(x)coth(x^2) .dx$










share|cite|improve this question











$endgroup$




Is there a closed form of this series
$$sum_{k=1}^infty e^{-sqrt{2 pi k}} $$
It can help to solve a very hard integral problem
$int_0^infty e^{-x}x sin(x)coth(x^2) .dx$







calculus sequences-and-series






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Dec 18 '18 at 21:10







Ahmad Albaw

















asked Dec 18 '18 at 20:57









Ahmad AlbawAhmad Albaw

103




103








  • 2




    $begingroup$
    What is that hard integral? Don't keep it for yourself please :D
    $endgroup$
    – Zacky
    Dec 18 '18 at 21:00










  • $begingroup$
    No closed form as per Wolfram Alpha. How did that sum arise ? What's the integral ?
    $endgroup$
    – Rebellos
    Dec 18 '18 at 21:04












  • $begingroup$
    Check it now it's edited
    $endgroup$
    – Ahmad Albaw
    Dec 18 '18 at 21:11










  • $begingroup$
    Sorry. Unsolvable........
    $endgroup$
    – Mostafa Ayaz
    Jan 5 at 7:20














  • 2




    $begingroup$
    What is that hard integral? Don't keep it for yourself please :D
    $endgroup$
    – Zacky
    Dec 18 '18 at 21:00










  • $begingroup$
    No closed form as per Wolfram Alpha. How did that sum arise ? What's the integral ?
    $endgroup$
    – Rebellos
    Dec 18 '18 at 21:04












  • $begingroup$
    Check it now it's edited
    $endgroup$
    – Ahmad Albaw
    Dec 18 '18 at 21:11










  • $begingroup$
    Sorry. Unsolvable........
    $endgroup$
    – Mostafa Ayaz
    Jan 5 at 7:20








2




2




$begingroup$
What is that hard integral? Don't keep it for yourself please :D
$endgroup$
– Zacky
Dec 18 '18 at 21:00




$begingroup$
What is that hard integral? Don't keep it for yourself please :D
$endgroup$
– Zacky
Dec 18 '18 at 21:00












$begingroup$
No closed form as per Wolfram Alpha. How did that sum arise ? What's the integral ?
$endgroup$
– Rebellos
Dec 18 '18 at 21:04






$begingroup$
No closed form as per Wolfram Alpha. How did that sum arise ? What's the integral ?
$endgroup$
– Rebellos
Dec 18 '18 at 21:04














$begingroup$
Check it now it's edited
$endgroup$
– Ahmad Albaw
Dec 18 '18 at 21:11




$begingroup$
Check it now it's edited
$endgroup$
– Ahmad Albaw
Dec 18 '18 at 21:11












$begingroup$
Sorry. Unsolvable........
$endgroup$
– Mostafa Ayaz
Jan 5 at 7:20




$begingroup$
Sorry. Unsolvable........
$endgroup$
– Mostafa Ayaz
Jan 5 at 7:20










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