We present searches on Heavy Majorana neutrinos in events with same-sign lepton pairs and jets,
using the collision data collected with the CMS detector at a centre-of-mass energy 13 TeV.
The search range is extended to 20 GeV and 1500 GeV,
lower and upper bound respectively,
compared to the previous analysis using 8 TeV data.
The vector boson fusion production channel is considered as well as the s-channel,
which improves the sensitivities for mass above by several hundreds of GeV.
We set upper limits on muon mixing squared, electron mixing squared, and muon-electron cross mixing.