
Crack-free Walls
Problem 215
Published on Friday, 31st October 2008, 01:00 pm; Solved by 2075Consider the problem of building a wall out of 2
1 and 3
1 bricks (horizontal
vertical dimensions) such that, for extra strength, the gaps between horizontally-adjacent bricks never line up in consecutive layers, i.e. never form a "running crack".
For example, the following 9
3 wall is not acceptable due to the running crack shown in red:
There are eight ways of forming a crack-free 9
3 wall, written W(9,3) = 8.
Calculate W(32,10).