## Abstract

Let 0 < lambda <= 1, lambda is not an element of{2/4, 2/7, 2/10, 2/13, ... }, be a real and p a prime number, with [p,p + lambda p] containing at least two primes. Denote by f(lambda)(p) the largest integer which cannot be written as a sum of primes from [p,p + lambda p]. Then f(lambda)(p) similar to [2 + 2/lambda] p,as p goes to infinity. Further a question of Wilf about the "Money-Changing ...

## Abstract

Let 0 < lambda <= 1, lambda is not an element of{2/4, 2/7, 2/10, 2/13, ... }, be a real and p a prime number, with [p,p + lambda p] containing at least two primes. Denote by f(lambda)(p) the largest integer which cannot be written as a sum of primes from [p,p + lambda p]. Then f(lambda)(p) similar to [2 + 2/lambda] p,as p goes to infinity. Further a question of Wilf about the "Money-Changing Problem" has a positive answer for all semigroups of multiplicity p containing the primes from [p, 2p]. In particular, this holds for the semigroup generated by all primes not less than p. The latter special case was already shown in a previous paper.