About: http://webisa.webdatacommons.org/80857103

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	For the second question, one of the reasons that they are considered useful is that there is a relatively straightforward way of testing if a Mersenne number is actually a prime or not.
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com