  In view of the good agreement between the LHCb prompt-eta(c) data at
sqrt(s)=7 and 8 TeV and the NLO colour-singlet model predictions --i.e. the
leading v^2 NRQCD contribution--, we provide predictions in the LHCb acceptance
for the forthcoming 13 TeV analysis bearing on data taken during the LHC Run2.
We also provide predictions for sqrt(s)=115 GeV for proton-hydrogen collisions
in the fixed-target mode which could be studied during the LHC Run3. Our
predictions are complemented by a full theoretical uncertainty analysis. In
addition to cross section predictions, we elaborate on the uncertainties on the
p bar-p branching ratio --necessary for data-theory comparison-- and discuss
other usable branching fractions for future studies.
