Let
f be a Hecke eigencusp form of even integral weight
k or Maass cusp form for the full modular group
SL2(Z). Denote by
f46bfc69c0c9fcaa9cf4e" title="Click to view the MathML source">λsymmf(n) the
nth normalized coefficient of the Dirichlet expansion of the
mth symmetric power
L-function associated to
f. In this paper, we establish some bounds for
which improve the corresponding results of Lau & Lü
[8].