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2008 The van der Waerden Number $W(2,6)$ Is 1132
Michal Kouril, Jerome L. Paul
Experiment. Math. 17(1): 53-61 (2008).


We have verified that the van der Waerden number $W(2, 6)$ is 1132, that is, 1132 is the smallest integer n = W(2, 6) such that whenever the set of integers {1, 2, . . . , $n$} is 2-colored, there exists a monochromatic arithmetic progression of length 6. This was accomplished by applying special preprocessing techniques that drastically reduced the required search space. The exhaustive search showing that $W(2, 6)$ = 1132 was carried out by formulating the problem as a satisfiability (SAT) question for a Boolean formula in conjunctive normal form (CNF), and then using a SAT solver specifically designed for the problem. The parallel backtracking computation was run over multiple Beowulf clusters, and in the last phase, field programmable gate arrays (FPGAs) were used to speed up the search. The fact that $W(2, 6)$ > 1131 was shown previously by the first author.


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Michal Kouril. Jerome L. Paul. "The van der Waerden Number $W(2,6)$ Is 1132." Experiment. Math. 17 (1) 53 - 61, 2008.


Published: 2008
First available in Project Euclid: 18 November 2008

zbMATH: 1151.05048
MathSciNet: MR2410115

Primary: 05D10 , 68R05

Keywords: Beowulf clusters , combinatorics , FPGAs , high-performance computing , Van der Waerden numbers

Rights: Copyright © 2008 A K Peters, Ltd.

Vol.17 • No. 1 • 2008
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