Does the number $2.3\,5\,7\,11\,13\ldots$ exist and, if so, is it rational or irrational &/or transcendental?
37826
Is $0.23571113171923293137\dots$ transcendental?
147410
ArcTan(2) a rational multiple of $\pi$?
91101
Proving $\sqrt2$ is irrational
151355
Are cardinal numbers well defined? Or could we have something like $\aleph_{1/2}$?
21237
$\sqrt{6}-\sqrt{2}-\sqrt{3}$ is irrational
51191
Does a negative number really exist?
88429
Prove $\sqrt{2} + \sqrt{5}$ is irrational
28230
What bizarrities lurk within the decimal expansion of an irrational number?
75204
Irrationality $\sqrt{2}$ with ideal
95702
Remarkable/unexpected rational numbers
67605
Different proof that $\sqrt{2}$ is irrational
62792
Can sum of a rational number and its reciprocal be an integer?
151325
(How to/Can I) show irrational numbers?
48975
Transcendental numbers and irrationality measure
126816
Question of remainder on dividing by 7
53945
The square root of a prime number is irrational
76282
Prime number expressible as $2^2+3^3+5^5+7^7+11^{11}+\cdots$