“…It is important to underline that in some particular configurations of the parameters some terms of the asymptotic (but not the dominant term) could be incorporated in the error. Despite the apparently complicated form of the terms, it is not difficult to recognize the results obtained in the previous work on this topic, for example setting d = 2, h = 0 and r = (1, 1) (the Goldbach numbers case [22]) or r = ( 1 , 2 ) , 1 ≤ 1 ≤ 2 integers (the generalized Goldbach numbers case [23]). Furthermore, it is quite natural to conjecture that at least the main term of this asymptotic is valid for k ≥ 0 instead of k > d+h 2 as suggested by similar studies but with other techniques (see, e.g., the papers by the present authors [10] and with Languasco [8]).…”