PROMYS Guessing Game 2007

(Algebraic Number Theory and primes of the form p = x2 + m*y2)

Rules:

Guess the number 1 <= n <= 100 by using the following hints (in order). If you correctly answer the questions then you will have a unique answer for n at the end. All work must be done by hand, so no calculators/computers are allowed! Clues are generally in increasing order of difficulty. Have Fun! =)

Clues:

  1. All of the prime divisors of n are inert in the maximal totally real subfield of K := Q(\sqrt{-6},\sqrt{-30}), and at least one of the prime divisors of n ramifies in K.

  2. The degree d of the maximal unramified abelian extension of Q(\sqrt{-39}) divides n.

  3. The number n is not constructible.

  4. Let m be the ratio described in Clue 2 (i.e. m = n/d).  Then the ninth Mersenne prime p := 261 - 1 is not of the form x2 + m*y2, where x and y are integers.



Check yourself:

  1. Number of possibilities, List of Possibilities, Explanation

  2. Number of possibilities, List of Possibilities, Explanation (in progress)

  3. Number of possibilities, List of Possibilities, Explanation (coming soon)

  4. Number of possibilities, List of Possibilities, Explanation (coming soon)

For a complete computational solution in the SAGE Computer Algebra system (this solution is cheating), click here. (coming soon)