HW #4. Due Wed, Feb 18, 1998. Given on Feb 11. Math 365. Number Theory. Spring 1998. Use Matlab for the following 2 problems. Problem 1. Find the minimal twin pair of primes >100000. Problem 2*. List all numbers <10000 which can be represented as a sum of two cubes (of pos. integers) in more than one way (the order is ignored; thus the representations 8+27 and 27+8 are considered to be the same). _____________________________________ Without computers: Problem 3. Find the largest n for which 3^n | 1000! . Problem 4*. Denote c(n)=(2n)!/(n!)^2. Find minimal n such that 25 | c(n), or prove that such n does not exist. Problem 5. Find the sum of the inverses of positive divisors of 3000. Problem 6. Let p>10 be a prime. Prove that the list 1,2,3,4,5,6 contains at least 3 quadratic residues. ----------------------------------------------- New challenge problem. Prove: Problem. Prove: The sum of [n/k] mu(k) over k=1,2,..., n is equal to 1, for every n>0. (mu(x) stands for the Mobius function.)