We investigate the efficiency of noninteger n-generalized exponential type orbitals in energy calculations of isoelectronic series of atoms from Be to Ne and K [Ar]4s(0)3d(1) (2D) and Cr+ [Ar]4s(0) 3d(5) (6S) using combined Hartree-Fock-Roothaan theory. The results of calculations are compared with the values obtained in literature. All of the nonlinear parameters are fully optimized. It is shown that the use of noninteger n-generalized exponential type orbitals in atomic electronic structure calculations gives the superior agreement with numerical Hartree-Fock calculations. The minimum energy error, which is 0.00204432 Hartree, is observed for the neutral Be atom with respect to corresponding numerical Hartree-Fock result.