a1 Geismar Landstrasse 97, 3400 Göttingen, West Germany
The determination of the minimal s such that all large natural numbers n admit a representation as
is an interesting problem in the additive theory of numbers and has a considerable literature, For historical comments the reader is referred to the author's paper  where the best currently known result is proved. The purpose here is a further improvement.
(Received May 06 1987)