是啊。:)YWY 写了: ↑1月 21, 2024, 12:44 pm 难题啊
https://en.wikipedia.org/wiki/Landau%27s_problems
Near-square primes
Landau's fourth problem asked whether there are infinitely many primes which are of the form p=n^{2}+1} for integer n. (The list of known primes of this form is A002496.) The existence of infinitely many such primes would follow as a consequence of other number-theoretic conjectures such as the Bunyakovsky conjecture and Bateman–Horn conjecture. As of 2023, this problem is open.
4k+1素数可以写成一个平方和,这是一个著名的Fermat定理。我刚看了一眼证明,一个字,不容易。
和素数有关的定理,大多数都不容易。因为素数不能以代数方程的形式定义,它是否定形式定义的,也就是说它穿透所有的阶数。
这个问题改成x2+y2形式的素数,就简单了。因为所有的4k+1素数都可以表示为x2+y2。
但是固定任意一个平方数,它应该还是成立的,比如x2+4形式的素数,也应该是无穷多。
另外不一定是平方数,x2+2形式的素数,应该也是无穷多。