We determine the asymptotic behavior of the l p -norms of the sequence of Taylor coefficients of b n , where b = z−λ 1−λz is an automorphism of the unit disk, p ∈ [1, ∞], and n is large. It is known that in the parameter range p ∈ [1, 2] a sharp upper boundholds. In this article we find that this estimate is valid even when p ∈ [1, 4). We prove thatWe prove that our upper bounds are sharp as n tends to ∞ i.e. they have the correct asymptotic n dependence.the elementary Blaschke factor corresponding to λ. Clearly |b λ (z)| = 1 is equivalent to z ∈ ∂D. For any n we have that B = b n is a bounded, holomorphic on D and as such posses a natural identification with its boundary behavior on ∂D [NN]. It is well known that the Taylor-and Fourier-coefficients of such functions can be identified [NN] and we will use these terms interchangeably in what follows. Let B = k≥0 B(k)z k denote the Taylor expansion of B = b n . We writefor the usual l p -norm of the sequence of Taylor coefficients of B. In the limit of large p we set ||B|| l∞ := sup k | B(k)|. We observe that our l p -norms only depend on the absolute