Curious Corridors of Numbers
Each row begins with the number 1 at the left.
Skip counting by 2, 3, 4, 5, and so on gives the rest of each row.
The diagram can be continued as far as desired.
- idea from Math Puzzles & Games, by Michael Holt, pg 27

Adding the numbers in each L-shaped region forms a well known mathematical sequence.
What pattern shows up?
Another mathematical pattern is formed by the numbers along the diagonal.
What pattern is this?