About: http://webisa.webdatacommons.org/56408084

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	21 TWENTY-FIVE ??? ??? 25 is 5?? (a square) and a 5??5 grid is the smallest square that can have every cell visited by a knight (chess piece) using normal moves but, apart from that, this clue has defeated me.
http://www.w3.org/ns/prov#wasQuotedFrom	fifteensquared.net