Heegner Number

In number theory, a Heegner number is a square-free positive integer d such that the imaginary quadratic field Q(√−d) has class number 1. Equivalently, its ring of integers has unique factorization.

The determination of such numbers is a special case of the class number problem, and they underlie several striking results in number theory.

According to the Stark–Heegner theorem there are precisely nine Heegner numbers:

1, 2, 3, 7, 11, 19, 43, 67, 163.

This result was conjectured by Gauss and proven by Kurt Heegner in 1952.

Read more about Heegner Number:  Euler's Prime-generating Polynomial, Almost Integers and Ramanujan's Constant, Other Heegner Numbers, Consecutive Primes

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