The official definition of the MRB constant is found in Mathworld at http://mathworld.wolfram.com/MRBConstant.html.
For a couple of years now, you could read more about it in Wikipedia at
http://en.wikipedia.org/wiki/MRB_constant, and you still can.
However, in the Wikipedia article someone asked for a reference for the irrationality of the MRB constant. At first I thought, I could write an expert or two and they could give me a quick proof of its irrationality; however, when I wrote one of the leading experts on constants about the issue, he told me that it could take a lifetime for someone to prove, and even then the proof might not be right. Thus I figured I’ve no time to waste. I started to write down some ideas that might help prove it on mapleprimes at http://www.mapleprimes.com/posts/101425-Could-The-MRB-Constant-Be-Rational.
You might not be too familiar with writing proofs, but a proof is simply an explanation of why some statement is true using only statements that are known to be absolutely true. If on the other hand you think you might be able to help me with it, please do so.
I could use all the help I can get so please consider passing this along, and I thank you in advance.
Marvin Ray Burns