Question 65
Find all positive integers of form $\overline{abcd}$ such that
$$
\overline{abcd} = a^{a+b+c+d} - a^{-a+b-c+d} + a.
$$
$$
\overline{abcd} = a^{a+b+c+d} - a^{-a+b-c+d} + a.
$$
MathNet 2019-part-06 — 184 problems (EN–VI) Question 65
Math Olympiad Vault · MathNet 2019-part-06 — 184 problems (EN–VI)