Domino dissections of a board
Source: Russian TST 2014, Day 11 P1 (Groups A & B)
January 8, 2024
boarddominoescombinatorics
Problem Statement
On each non-boundary unit segment of an chessboard, we write the number of dissections of the board into dominoes in which this segment lies on the border of a domino. What is the last digit of the sum of all the written numbers?