Charm production in pp collisions at 5 and 13 TeV at LHCb

The start of the second run of the Large Hadron collider opened a new energy regime in which QCD predictions for charm meson production may be precisely tested. LHCb is uniquely suited to make measurements of production cross-sections in the forward region, as our sensitivity to the gluon parton distribution function in the small-x region can be used to improve the understand- ing of the proton structure. Having measured charm hadron production cross-sections at multiple proton-proton collision energies, LHCb now has access to cross-section ratios, a more precise class of observables that benefit from cancellation of both experimental and theoretical uncertain- ties, providing a new sensitive test of the QCD calculations. This paper will give an overview on charm hadron production measurements by LHCb in Run 2 at proton-proton center-of-mass energies of 5 and 13 TeV.