English

Seeds for Generalized Taxicab Numbers

Number Theory 2019-01-29 v1

Abstract

The generalized taxicab number T(n,m,t)T(n,m,t) is equal to the smallest number that is the sum of nn positive mmth powers in tt ways. This definition is inspired by Ramanujan's observation that 1729=13+123=93+1031729 = 1^3+ 12^3 =9^3 + 10^3 is the smallest number that is the sum of two cubes in two ways and thus 1729=T(2,3,2)1729= T(2,3,2). In this paper we prove that for any given positive integers mm and tt, there exists a number ss such T(s+k,m,t)=T(s,m,t)+kT(s+k,m,t) =T(s,m,t) +k for every k0k \geq 0. The smallest such ss is termed the seed for the generalized taxicab number. Furthermore, we find explicit expressions for this seed number when the number of ways tt is 2 or 3 and present a conjecture for t4t \geq 4 ways.

Cite

@article{arxiv.1901.09053,
  title  = {Seeds for Generalized Taxicab Numbers},
  author = {Jeffrey. H. Dinitz and Richard Games and Robert Roth},
  journal= {arXiv preprint arXiv:1901.09053},
  year   = {2019}
}
R2 v1 2026-06-23T07:22:37.389Z