Abstract
The distance-regular graphsΛ of type IIB in Bannai and Ito [1] have intersection numbers of the form
whered is the diameter of Λ, andh, x, andt are complex constants. In this paper we show a graph of type IIB and diameterd (3≦d) is either the antipodal quotient of the Hamming graphH(2d+1,2), or has the same intersection numbers as the antipodal quotient ofH(2d, 2).
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References
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