duplicates These two question seem like duplicates to me. In which direction to close?

219693: Finding a closed formula for $1\cdot2\cdot3\cdots k +\dots + n(n+1)(n+2)\cdots(k+n-1)$

2021231: How can I derive what is $1\cdot 2\cdot 3\cdot 4 + 2\cdot 3\cdot 4\cdot 5+ 3\cdot 4\cdot 5\cdot 6+\cdots + (n-3)(n-2)(n-1)(n)$ ??

Ok so maybe not duplicates, on is about arbitrary $k$, the other is the case $k=4$.

@MartinSleziak fyi, I have found many of my old questions that need to be closed. They are horribly written, about non-mathematical things and generally spamful.

I have voted to close them. Feel free to back me up on this.

[ SmokeDetector | MS ] Misleading link in body: Probability - Conditional (1-1) by Ahmed Asaad on math.stackexchange.com

duplicates 2045448: How to determine the convergence of $\sum_{n\geq 2}{} \frac{(-1)^{n}}{(-1)^n+n}$? is currently in the close votes review and it has two off-topic/missing context close votes.

These two question seem to be about the same series:

1496386: Determine if $\sum_{n=2}^{\infty} \frac{(-1)^n}{n+(-1)^n} $converges or diverges

843093: Does this series with alternating elements converge: $\sum_{k=10}^{+\infty}\frac{(-1)^k}{k+(-1)^k}$?

Which of them would be be optimal choice of the duplicate target?

The today's question (2045448) has some nice answers which are probably worth saving.