Let x(0),...,x(n), be an additive chain of length n+1 with x(0)=1 and satisfying x(k) = x(k-1) + x(j) for some j < k. a(n) is the number of distinct possible values taken on by x(n).

A075529

Let x(0),...,x(n), be an additive chain of length n+1 with x(0)=1 and satisfying x(k) = x(k-1) + x(j) for some j < k. a(n) is the number of distinct possible values taken on by x(n).