Two New Techniques for Computing Extremal h-bases Ak

A k ={1, a 2 ,..., a k } is an h-basis for n if every positive integer c n can be expressed as the sum of more than h values a i ; an extremal h-basis A k is one for which n is as large as possible. Computing such bases has become known as the Postage Stamp Problem, and this paper describes two new techniques-one appropriate for large k, and the other for large h-which help extend known results in both dimensions. The results themselves are presented as an Appendix