  As a hot issue, exploring exotic pentaquarks is full of challenges and
opportunities for both theorist and experimentalist. In this work, we focus on
a type of pentaquark with the $QQqq\bar{q}$ ($Q=b,c$; $q=u,d,s$) configuration,
where their mass spectrum is estimated systematically. Especially, our result
indicates that there may exist some stable or narrow exotic pentaquark states.
Obviously, our study may provides valuable information for further experimental
search for the $QQqq\bar{q}$ pentaquarks. With the running of LHCb and
forthcoming Belle II, we have a reason to believe that these predictions
present here can be tested.
