My second talk will not be a continuation of sudoku, however it will be on something similar called magic squares. Recalling from last talk Latin squares of 3×3 dimension make up the 9×9 sudoku board where no number is repeated in any column or row or square. A magic square is similar in that it is an arrangement of numbers (usually integers) in a square grid, where the numbers in each row, and in each column, and the numbers that run diagonally in both directions, all add up to the same number. It also has nxn or n^2 dimensions only. I will discuss further the history as well as methods to construct some.
This is the article I used last time for the sudoku: The Science behind SUDOKU, BY JEAN-PAUL DELAHAYE, Scientific American, June 2006.