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Consider the equation over the ring R = Z [ ω ] , where ω is a primitive third root of unity. It is an important fact that R is a unique factorization domain; any element can be factored as a product of irreducibles, unique up to ordering and scaling by a unit. There is a norm function N : R → Z defined by N ( a − b ω ) = ( a − b ω ) ( a − b ω 2 ) = a 2 + a b + b 2 , and the nice thing about it is that it is multiplicative: N ( α β ) = N ( α ) N ( β ) .
Then we get N ( a − b ω ) = ( a − b ω ) ( a − b ω 2 ) = 2 0 1 7 , and the prime 2 0 1 7 splits as the product of two irreducibles whose norm is 2 0 1 7 . (Anything whose norm is 2 0 1 7 must be irreducible because if it factored, the norm of one of the factors would have to be 1, so it would be a unit.)
By inspection, we can see N ( 4 1 − 7 ω ) = 4 1 2 + 7 ⋅ 4 1 + 7 2 = 2 0 1 7 , so there is at least one solution. (For primes p not divisible by 3, a solution exists if and only if p ≡ 1 mod 3 , by some basic algebraic number theory machinery.)
How many other solutions are there? Well, the factorization ( 4 1 − 7 ω ) ( 4 1 − 7 ω 2 ) = 2 0 1 7 is unique up to switching the factors and multiplying by a unit. There are exactly six units in Z [ ω ] , consisting of the sixth roots of unity generated by 1 + ω (this can be verified by fancy arguments involving Dirichlet's unit theorem, or pretty easily by direct computation). So there are a total of 2 ⋅ 6 = 1 2 distinct solutions. For completeness, I'll list them here:
( ± 4 1 , ± 7 ) ( ± 4 8 , ∓ 4 1 ) ( ± 4 8 , ∓ 7 ) ( ± 7 , ± 4 1 ) ( ± 4 1 , ∓ 4 8 ) ( ± 7 , ∓ 4 8 )