function a = A368059( max_n )
    a = 3; m = 3; cache = {};
    for n = 2:max_n
        [v, cache] = sumvector(a(n-1), cache);
        k = m; 
        [vk, cache] = sumvector(k, cache);
        while isempty(intersect(v,vk))||~isempty(find(a==k,1))
            k = k+1; 
            [vk, cache] = sumvector(k, cache);
        end
        if k == m+1
            m = m+1;
        end
        a(n) = k;
    end
end
function [v, cache] = sumvector(k,cache)
    if k > length(cache)
        v = sumv(k);
        cache{k} = v;
    else
        if isempty(cache{k})
            v = sumv(k);
            cache{k} = v;
        else
            v = cache{k};
        end
    end
end
function v = sumv(k)
   d = divisors(k);
   v = d(1:floor((length(d)+1)/2))+d(end:-1:1+floor(length(d)/2));
end