Question 116
For positive integers $n$, define
$$
a_{n} = 3^{n} + 6^{n} - 2^{n}.
$$
Find, with proof, all primes that do not divide any of the numbers $a_{1}, a_{2}, a_{3}, \ldots$.
$$
a_{n} = 3^{n} + 6^{n} - 2^{n}.
$$
Find, with proof, all primes that do not divide any of the numbers $a_{1}, a_{2}, a_{3}, \ldots$.