1. Verify that Φ(84)=Φ(12)Φ(7) by finding a bijection between ordered pairs. 5 |3 q5 D7 z& n: m2. Programme Rowland's formular and verify his results. Try different starting values and see what happens.) n# N! A/ D, X4 c+ P3 n
3. Verify the following result called Wilson's Theory: An integer n is prime if and only if (n-1)!≡-1(mod n ) for the cases n=2,3,4,5...,10. Can this be used as an efficent test for a prime? ' c3 K+ \( g5 v& i' i) p& H4. Prove that if n is a pseudoprime to base 2 then 2^n-1 is a pseudoprime to base 2 also. # G* ]+ y, r9 j3 v R8 [5. IS 341 a pseudoprime to the base 5? Is 341 a pseudoprime to base 7? Is 341 a pseudoprime to base 13?+ J# L& T* l0 D# i
6. Verify that 1729 and 2465 are Carmichael numbers using the Korselt criterion and directly. ' R6 T6 {& I2 f; ~/ {7. Can pq be a Carmichael number where p and q are odd primes. ' B1 ^, z; W* R- V8. Find a k such that 6k+1,12k+1,18k+1 are all prime numbers. Prove that then n=(6k+1)(12k+1)(18k+1) is a Carmichael number., E& y: G& T0 x0 |
9. Apply the Rabin-Miller test to n=1729 and n=24651 G) Y+ q7 n A
10. Let n=667. For which a is a^667≡a(mod 667). Do the same for n=833. You might need to write a ** programme in Maple.