is devoted to the theory of countable systems of ordinary differential equations. The monographs of Samoilenko and R. I. Petryshyn cover a broad class of qualitative problems in the theory of nonlinear dynamical systems on a torus. Samoilenko is the author of about 400 scientific works, including 30 monographs and 15 textbooks, most of which have been translated into foreign languages. His monographs made an important contribution to mathematical science and education. According to MathSciNet, the scientific papers of Samoilenko were cited 336 times by 208 authors. The scientific interests of Samoilenko covered a broad range of important problems in the qualitative theory of differential equations, nonlinear mechanics, and the theory of nonlinear oscillations. His deep results in the theory of multifrequency oscillations, perturbation theory of toroidal manifolds, asymptotic methods of nonlinear mechanics, theory of impulsive systems, theory of differential equations with delay, and theory of boundary-value problems were highly appreciated in Ukraine and abroad. Academician Samoilenko was the founder of a scientific school in the theory of multifrequency oscillations and theory of impulsive systems recognized by the international mathematical community. His successful many-year guidance of the Institute of Mathematics of the Ukrainian National Academy of Sciences furthered the rapid development of mathematics in the Ukraine and the continuation of the best traditions of the world-known Bogolyubov – Krylov – Mitropolskiy Kyiv scientific school. The worldwide recognition of Samoilenko's mathematical results is illustrated by notions well known in the mathematical literature such as the Samoilenko numerical-analytic method and the Samoilenko – Green function (the kernel of an integral operator related to the problem of an invariant torus of a dynamical system). Samoilenko gave much attention to training scientists of the highest qualification. For many years, he had given lectures at the Shevchenko Kyiv National University and the "Kyiv Polytechnic Institute" National Technical University and guided the scientific work of postgraduate and doctoral students. Despite the extremely busy schedule of his work as the Director of the Institute of Mathematics of the Ukrainian National Academy of Sciences for about 20 last years (since 2006, he was the Academician-Secretary of the Department of Mathematics at the National Academy of Sciences of Ukraine), Samoilenko found time for organizational and public activities. In particular, Samoilenko was the President of the "Foundation for Support of the Development of Mathematical Sciences" All-Ukrainian charity organization. Many young talents from the "small homeland" of Samoilenko (Malynshchyna) are grateful