A simplified variant of the method of computation of the Fourier coefficients of a series

Making use of the results of Golubeva and Fomenko (Zapiski Nauchn. Sem. Leningr. Otd. Mat. Inst., 71, 85–95 (1977)), one computes the Fourier coefficients of the nonanalytic Eisenstein series relative to $Sp_2(\mathbf Z)$ by a method which is simpler than that of Kaufhold (Math. Ann., 137, No. 5, 454–476 (1959)).