The oxycarbonate Sr7Co4(CO3)O-11.36 exhibits a peculiar structure that has been characterized by combining transmission electron microscopy analyses and neutron diffraction. It consists of a regular intergrowth between the m = 2 and carbonated m = 3 members of the Srm+1ComO3m+1 Ruddlesden-Popper (RP) series, Sr3Co2O5.87 and Sr4Co2(CO3)O-5.49, respectively. A description of the structure is proposed to provide identification of the different building blocks. This material is semiconducting and presents a complex magnetic behavior, characteristic of what is observed for the RP2 or RP3 series, with a cobalt valency close to 2.7.