Problem of the Fortnight #5

 

Sudoku Jr. Madness!

               

The Sudoku Jr. puzzle is a 4x4 array in which each row, each column, and each 2x2 corner contains the numbers 1, 2, 3, 4 exactly once (see below for a sample).  How many distinct Sudoku Jr. puzzles are there?

                                   

 

 

 

 

 

 

 

 

Solutions are due by 4pm on Friday, November 4th in Goodrich 108

Problem courtesy of a mysterious source.