## Faculty Publications

Article

3-2019

#### Publication Source

Discrete Mathematics

342

3

777

783

Elsevier

#### ISSN

0012-365X

Charles A. Cusack, Airat Bekmetjev, Mark Powers, Two-pebbling and odd-two-pebbling are not equivalent, Discrete Mathematics, Volume 342, Issue 3, 2019, Pages 777-783, https://doi.org/10.1016/j.disc.2018.10.030.

#### Abstract

Let G be a connected graph. A configuration of pebbles assigns a nonnegative integer number of pebbles to each vertex of G. A move consists of removing two pebbles from one vertex and placing one pebble on an adjacent vertex. A configuration is solvable if any vertex can get at least one pebble through a sequence of moves. The pebbling number of G, denoted π(G), is the smallest integer such that any configuration of π(G) pebbles on G is solvable. A graph has the two-pebbling property if after placing more than 2π(G) -- q pebbles on G, where q is the number of vertices with pebbles, there is a sequence of moves so that at least two pebbles can be placed on any vertex. A graph has the odd-two-pebbling property if after placing more than 2π(G) -- r pebbles on G, where r is the number of vertices with an odd number of pebbles, there is a sequence of moves so that at least two pebbles can be placed on any vertex. In this paper, we prove that the two-pebbling and odd-two-pebbling properties are not equivalent.

#### Keywords

graph pebbling, Lemke graph, two-pebbling, odd-two-pebbling

COinS

#### DOI

https://doi.org/10.1016/j.disc.2018.10.030