Question 27
Find the number of the sequences $\{a_{n}\}_{n=1}^{\infty}$ of integers such that
$$
a_{n}+a_{n+1}=2 a_{n+2} a_{n+3}+2005
$$
for every $n$.
$$
a_{n}+a_{n+1}=2 a_{n+2} a_{n+3}+2005
$$
for every $n$.
MathNet 2005 — Part 02 Question 27
Math Olympiad Vault · MathNet 2005 — Part 02