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Generalized H-fold sumset and Subsequence sum

Mohan, Ram Krishna Pandey

Abstract

Let $A$ and $H$ be nonempty finite sets of integers and positive integers, respectively. The generalized $H$-fold sumset, denoted by $H^{(r)}A$, is the union of the sumsets $h^{(r)}A$ for $h\in H$ where, the sumset $h^{(r)}A$ is the set of all integers that can be represented as a sum of $h$ elements from $A$ with no summand in the representation appearing more than $r$ times. In this paper, we find the optimal lower bound for the cardinality of $H^{(r)}A$, i.e., for $|H^{(r)}A|$ and the structure of the underlying sets $A$ and $H$ when $|H^{(r)}A|$ is equal to the optimal lower bound in the cases $A$ contains only positive integers and $A$ contains only nonnegative integers. This generalizes recent results of Bhanja. Furthermore, with a particular set $H$, since $H^{(r)}A$ generalizes subsequence sum and hence subset sum, we get several results of subsequence sums and subset sums as special cases.

Generalized H-fold sumset and Subsequence sum

Abstract

Let and be nonempty finite sets of integers and positive integers, respectively. The generalized -fold sumset, denoted by , is the union of the sumsets for where, the sumset is the set of all integers that can be represented as a sum of elements from with no summand in the representation appearing more than times. In this paper, we find the optimal lower bound for the cardinality of , i.e., for and the structure of the underlying sets and when is equal to the optimal lower bound in the cases contains only positive integers and contains only nonnegative integers. This generalizes recent results of Bhanja. Furthermore, with a particular set , since generalizes subsequence sum and hence subset sum, we get several results of subsequence sums and subset sums as special cases.
Paper Structure (5 sections, 22 theorems, 138 equations)

This paper contains 5 sections, 22 theorems, 138 equations.

Key Result

Theorem 1.1

NATHAN1996 Let $h\geq 1$, and let $A$ be a nonempty finite set of integers. Then This lower bound is best possible. Furthermore, if $\left|hA\right|$ attains this lower bound with $h \geq 2$, then $A$ is an arithmetic progression.

Theorems & Definitions (34)

  • Theorem 1.1
  • Theorem 1.2
  • Theorem 1.3
  • Theorem 1.4
  • Theorem 1.5
  • Theorem 1.6
  • Theorem 1.7
  • Theorem 1.8
  • Theorem 2.1
  • proof
  • ...and 24 more