A series of homologous silicides, Lnn(n+1)+xNin(n+5)+ySi(n+1)(n+2)-z (n = 4-6), has been discovered during systematic explorations in the central part of the La-Ni-Si system at 1000 C and the following screening of the isocompositional samples with Ce, Pr and Gd. All compounds crystallize in the hexagonal space group P63/m and their structures are based on equilateral triangular assemblies composed of a finite number of fused La@Ni6Si6 hexagonal prisms extending along the c axis. The new series adds to the big family of phosphides and arsenides representing so far a minor branch but with broad expansion possibilities. The formation of the row is mainly controlled by geometric factors allowing for further involvement of other transition metals and the p-block elements as well as potential structures with higher n.