Communities

Writing
Writing
Codidact Meta
Codidact Meta
The Great Outdoors
The Great Outdoors
Photography & Video
Photography & Video
Scientific Speculation
Scientific Speculation
Cooking
Cooking
Electrical Engineering
Electrical Engineering
Judaism
Judaism
Languages & Linguistics
Languages & Linguistics
Software Development
Software Development
Mathematics
Mathematics
Christianity
Christianity
Code Golf
Code Golf
Music
Music
Physics
Physics
Linux Systems
Linux Systems
Power Users
Power Users
Tabletop RPGs
Tabletop RPGs
Community Proposals
Community Proposals
tag:snake search within a tag
answers:0 unanswered questions
user:xxxx search by author id
score:0.5 posts with 0.5+ score
"snake oil" exact phrase
votes:4 posts with 4+ votes
created:<1w created < 1 week ago
post_type:xxxx type of post
Search help
Notifications
Mark all as read See all your notifications »
Q&A

Post History

66%
+2 −0
Q&A Does the series $\sum_{n=1}^{\infty} \frac{n^n}{n!} e^{-n}$ converge?

2 answers  ·  posted 2mo ago by Snoopy‭  ·  last activity 2mo ago by Snoopy‭

#2: Post edited by user avatar Snoopy‭ · 2024-08-11T16:25:12Z (2 months ago)
  • **Problem**: Does the series $\sum_{n=1}^{\infty} \frac{n^n}{n!} e^{-n}$ converge?
  • **Note**: In many calculus textbook examples, series involving the factorial term $n!$ are typically analyzed using the [ratio test](https://en.wikipedia.org/wiki/Ratio_test). These exercises often skip a detailed examination of how rapidly $n!$ grows. However, the ratio test can often be inconclusive, requiring an understanding of the growth rate of $n!$.
  • The given series is a case where the ratio test is inconclusive, and there is no straightforward series available for direct comparison.
  • I will write my answer below. Different viewpoints or approaches to this problem are welcome.
  • **Problem**: Does the series $\sum_{n=1}^{\infty} \frac{n^n}{n!} e^{-n}$ converge?
  • **Note**: In many calculus textbook examples, series involving the factorial term $n!$ are typically analyzed using the [ratio test](https://en.wikipedia.org/wiki/Ratio_test). These exercises often skip a detailed examination of how rapidly $n!$ grows. However, the ratio test can often be inconclusive, requiring an understanding of the growth rate of $n!$.
  • The given series is a case where the ratio test is inconclusive, and there is no straightforward series available for direct comparison.
  • I will write my answers below. Different viewpoints or approaches to this problem are welcome.
#1: Initial revision by user avatar Snoopy‭ · 2024-08-11T13:24:14Z (2 months ago)
Does the series $\sum_{n=1}^{\infty} \frac{n^n}{n!} e^{-n}$ converge?
**Problem**: Does the series $\sum_{n=1}^{\infty} \frac{n^n}{n!} e^{-n}$ converge?

**Note**: In many calculus textbook examples, series involving the factorial term $n!$ are typically analyzed using the [ratio test](https://en.wikipedia.org/wiki/Ratio_test). These exercises often skip a detailed examination of how rapidly $n!$ grows. However, the ratio test can often be inconclusive, requiring an understanding of the growth rate of $n!$.

The given series is a case where the ratio test is inconclusive, and there is no straightforward series available for direct comparison.

I will write my answer below. Different viewpoints or approaches to this problem are welcome.