This afghan is closely related to a cushion I made about ten years ago. For some reason the idea resurfaced recently but I struggled to find an easy way to achieve my aim.

Strangely, seeing this gave me the final push because it was the kind of idea I had been thinking about and then I realised that was completely the wrong way for me.

Data Log is basically a log cabin design but it has a mathematical purpose, which will eventually be revealed.

June 10
I have completed about one-ninth of the afghan. I left the markers in place as they might give a clue to the maths behind this.

June 13
About one quarter done.

June 23
It’s about half done now but slowed down quite a bit as I have been doing a lot of hospital visiting in the past two weeks. I’ve managed to get some done on the long trips but it’s not the sort of situation where I can knit in the hospital.

July 10
Finished - but not finished. It looks good as it is but it does not yet reveal its mathematical meaning.

July 25
Now it really is finished and shows 1225 small squares. You can understand why it was difficult to find a method to show so many squares. It would have been a nightmare to make them individually. Doing it this way means it has the advantage of being able to add the grid, or not, as you prefer.

It represents where the 49th triangular number and 35th square number coincide.

This also happens with the number 36:
1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 = 36
6 x 6 = 36

The number 1225 is the next occasion when this happens. It does not happen again until 41616.