The s-wave bound state of the 4α + Λ system is investigated. The relevant solution to the Schrödinger equation is expanded in the basis formed by the eigenfunctions of Hamiltonian for the 4α subsystem. Differential equations for Yakubovsky components are employed to calculate basis functions. Phenomenological potentials for αα and αΛ interactions are used. In the 4α system, additional three-particle potentials for the interaction between α clusters are introduced in such a way as to reproduce the experimental data on the binding energies, the root-mean-square radii, and the charge form factors for the ¹²C and the ¹⁶O nucleus. The binding energy, the root-mean-square radius, and the hyperon distribution in the ground state of the ¹⁷_ΛO nucleus are calculated. The results of the calculations are in good agreement with those obtained on the basis of the ¹⁶O + Λ two-particle model with the phenomenological Woods-Saxon potential.