Theorem. For every even integer m there exists a representation of the form m=a(r)+a(s). If A(x) is the counting function of a(n)<=x, then A(x)=O(sqrt(x))and Omega(sqrt(x)). Conjecture. The sequence is minimal in the following sense: if any sequence has the counting function B(x)<=A(x) for all x>=1 and B(x) < A(x) for x>=x_0, then there exists an even integer N which is not expressible as a sum of two terms of such sequence.