1. Given: p is a prime number of the form 9k+1. This implies that p≡1(mod9).
2. Objective: Show that there exists an integer n such that p∣n3−3n+1.
3. Step 1: Since p≡1(mod9), we know that 9∣(p−1). This implies that p−1=9m for some integer m.
4. Step 2: Consider the finite field Fp2. Since p≡1(mod9), the multiplicative group Fp2∗ has order p2−1.
5. Step 3: The order of Fp2∗ is p2−1. Since p≡1(mod9), we have p2−1≡0(mod9). Therefore, 9∣(p2−1).
6. Step 4: There exists an element t in Fp2 with order 9. This is because the order of the multiplicative group Fp2∗ is divisible by 9.
7. Step 5: Consider the element t+t1 in Fp. We need to show that t+t1 satisfies the equation n3−3n+1≡0(modp).
8. Step 6: Compute (t+t1)3−3(t+t1)+1:
(t+t1)3=t3+3t+t3+t31
(t+t1)3−3(t+t1)+1=t3+t31+3(t+t1)−3(t+t1)+1
=t3+t31+1
9. Step 7: Since t has order 9, t9=1. Therefore, t6=t31. Substitute t6=t31 into the equation:
t3+t31+1=t3+t6+1=t3+t31+1=0
10. Step 8: Thus, (t+t1)3−3(t+t1)+1=0. Therefore, we can take n≡t+t1(modp).
Conclusion:
n≡t+t1(modp)