1. For $$n < 25$$
Representation: $$n = 5 \cdot a + b$$
$$L[n!] = (2^a \cdot L[a!] \cdot L[b!]) \pmod{10}$$
2. For $$25 \le n < 125$$
Representation: $$n = 25 \cdot a + b$$
$$L[n!] = (4^a \cdot L[a!] \cdot L[b!]) \pmod{10}$$
3. For $$n \ge 125$$
Representation: $$n = 125 \cdot a + b$$
$$L[n!] = (8^a \cdot L[a!] \cdot L[b!]) \pmod{10}$$
