  In the last decade a huge amount of articles has been published studying
pattern avoidance on permutations. From the point of view of enumeration,
typically one tries to count permutations avoiding certain patterns according
to their lengths. Here we tackle the problem of refining this enumeration by
considering the statistics "first/last entry". We give complete results for
every generalized patterns of type $(1,2)$ or $(2,1)$ as well as for some cases
of permutations avoiding a pair of generalized patterns of the above types.
