We discuss charm quark/antiquark and charmed meson production in association with one extra jet (gluon, quark, antiquark) at the LHC. The calculations are performed both in collinear and k_T-factorization approaches. Different unintegrated gluon distribution functions are used in the k_T-factorization approach. Several predictions for the LHC are presented. We show distributions in rapidity and transverse momenta of c/c̅ (or charmed mesons) and the associated jet as well as some two-dimensional

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... observables. Interesting correlation effects are predicted, e.g. in azimuthal angles φ_cc̅ and φ_c-jet. We have also discussed a relation of the 2 → 2 and 2 → 3 partonic calculations in the region of large transverse momenta of charm quarks/antiquarks as well as the similarity of the next-to-leading order collinear approach and the k_T-factorization approach with the KMR unintegrated parton distribution functions. Integrated cross sections for D^0 + jet production for ATLAS detector acceptance and for different cuts on jet transverse momenta are also presented.