Find D.I. Mendeleev’s elements, the relative atomic masses of which differ three times.

Helium and carbon: Ar (He) = 4; Ar (C) = 12;
Beryllium and aluminum: Ar (Be) = 9; Ar (Al) = 27;
Oxygen and titanium: Ar (O) = 16; Ar (Ti) = 48;
Silicon and krypton: Ar (Si) = 28; Ar (Kr) = 84;
Phosphorus and niobium: Ar (P) = 31; Ar (Nb) = 93;
Sulfur and molybdenum: Ar (S) = 32; Ar (Mo) = 96;
Titanium and neodymium: Ar (Ti) = 48; Ar (Nd) = 144;
Manganese and Holmium: Ar (Mn) = 55; Ar (Ho) = 165;
Copper and iridium: Ar (Cu) = 64; Ar (Ir) = 192;
Zinc and Platinum: Ar (Zn) = 65; Ar (Pt) = 195;
Galium and astatine: Ar (Ga) = 70; Ar (At) = 210;
Selenium and neptunium: Ar (Se) = 79; Ar (Np) = 237;
Krypton and Einsteinium: Ar (Kr) = 84; Ar (Es) = 252;
Molybdenum and ununpentium: Ar (Mo) = 96; Ar (Uup) = 288;
Technetium and ununseptium and ununoctium: Ar (Tc) = 98; Ar (Uus) = Ar (Uuo) = 294.