F^n
Maybe we should remove this operation, in favor of ZZ * AbstractSheaf.
i1 : X = abstractProjectiveSpace 1 o1 = X o1 : a flag bundle with subquotient ranks {2:1}
i2 : F = OO_X(1) o2 = F o2 : an abstract sheaf of rank 1 on X
i3 : chi F^10 o3 = 20