Data Log is a log cabin design with a mathematical purpose.

It is made using the traditional log cabin method, occasionally using two yarns in one section. The afghan in the photos was made in DK yarn but the pattern includes instructions for making it in any yarn of your choice, and for changing the size.

The grid is optional. It merely shows the mathematical idea more clearly.

The afghan demonstrates where triangular numbers and square numbers coincide.

A triangular number is the result of adding counting numbers.
A square number is the result of multiplying a number by itself.

Example:
Triangular: 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 = 36
Square: 6 x 6 = 36

The answers in this example coincide.

The afghan shows where the 49th triangular number and 35th square number coincide, giving 1225 small squares.

This does not happen again until 41616.

Buy the pattern using the link at the top of this page.

SaraBea has designed a crochet version of Data Log. It is called MAGIC: Blanket with numbers.