This has occured 23 times
Once. They went to the NCAA tournament for the first time in 2012 as a #15 seed.
5
13
Yes.In fact,in the 2013 NCAA men's basketball tournament, the #12 seed beat the #5 seed in three of the four regionals:California over UNLV 64-61 in the East; Oregon over Oklahoma State 68-55 in the Midwest; and Mississippi over Wisconsin 57-46 in the West.
Yes it has happened 2 times in 1986 and 1997
1 seed
UNC was a number 1 seed in the 2009 NCAA basketball tournament.
3
A 4 seed.
Wake Forest was a number 4 seed in the 2009 NCAA Basketball Tournament.
There have been three times in NCAA Men's Basketball history that no #1 seed has been in the Final Four. The only three years were 1980, 2006, and 2011 with the following teams included in their separate final fours: 1980: Louisville (#2 seed), Iowa (#5 seed), Purdue (#6 seed), and UCLA (#8 seed) 2006: UCLA (#2 seed), Florida (#3 seed), LSU (#4 seed), and George Mason (#11 seed) 2011: Butler (#8 seed), UConn (#3 seed), VCU (#11 seed), and Kentucky (#4 seed)