  The localization of electrons in the field of isolated nonmagnetic impurity
atoms on the surface of a nanotube in a magnetic field is considered. A model
of a Gaussian separable impurity potential capable of localizing an electron at
any intensity is used. The positions of the local level are found in the regime
of strong and weak localizations. The positions of the resonances are found,
their widths are estimated. They experience Aharonov-Bohm oscillations when the
magnetic flux in the tube changes. It is shown that the positions of the
resonances experience oscillations similar to the de Haas-van Alphen
oscillations, which are not associated with a magnetic field.
