Fan

FIG. 1 is a perspective view of a fan showing my new design. FIG. 2 is a front view thereof. FIG. 3 is a rear view thereof. FIG. 4 is a left side view thereof. FIG. 5 is a right side view thereof. FIG. 6 is a top view thereof. FIG. 7 is a bottom view thereof. FIG. 8 is a rear, right, bottom perspective view thereof. FIG. 9 is an enlarged detail view of area 9 shown in FIG. 1 . FIG. 10 is an enlarged detail view of area 10 shown in FIG. 4 . FIG. 11 is an enlarged detail view of area 11 shown in FIG. 5 ; and, FIG. 12 is an enlarged detail view of area 12 shown in FIG. 8 . The broken lines in the drawings depict portions of the fan that form no part of the claimed design.