A note on the squares of the form $\prod_{k=1}^n (2k^2+l)$ with $l$ odd

Russelle Guadalupe

Published 2022-01-03, updated 2023-12-11Version 2

Let $l$ be a positive odd integer. Using Cilleruelo's method, we establish an explicit lower bound $N_l$ depending on $l$ such that for all $n\geq N_l$, $\prod_{k=1}^n (2k^2+l)$ is not a square. As an application, we determine all values of $n$ such that $\prod_{k=1}^n (2k^2+l)$ is a square for certain values of $l$.