I just saw this one for sale. It is not in RIC, but examples are known from all four officinae (P,S,T,Q). Interestingly, this issue is in Maurice, but Bruun somehow did not include it in RIC VII.
Constantine I
circa A.D. 315
22mm 2.3gm
IMP CONSTANTINVS PF AVG, bust r., laureate, draped and cuirassed.
LIBERATOR ORBIS [The Liberator of the World], Emperor galloping r. over lion, r. raised.
In exergue R*P
It should come after RIC VII Rome 17