Radiative-nonrecoil corrections of order alpha² (Z alpha)⁵ to the Lamb shift

We present results for the corrections of order alpha^2 (Z alpha)^5 to the Lamb shift. We compute all the contributing Feynman diagrams in dimensional regularization and a general covariant gauge using a mixture of analytical and numerical methods. We confirm results obtained by other groups and improve their precision. Values of the 32 master integrals for this and similar problems are provided.