  Let F be a field of characteristic 0. We consider the algebra UT_m(F) of
upper triangular matrices of order m endowed with na elementar Z_m-grading
induced by the m-tuple phi=(0,0,1,...,m-2), then we compute its Y-proper graded
cocharacter sequence and we give the explicit formulas for the multiplicities
in the case m=2,3,4,5.
