RIC does not list this bust type (Y) with this obverse legend (1e). It should come before London 228. It is not in Huevelin either.
Constantine I
A.D. 310-12
22.5mm 3.7gm
CONSTANTINVS P AVG; bust left, laureate and cuirassed, r. holding spear forward, shield on l. arm.
PRINCIPI IVVENTVTIS [In honor of the Prince of Youth]; Prince standing facing, head left, holding a globe and spear, star in right field.
in exergue PLN
RIC VI London --
It sold for $440.43