# Teresa Downard

Mathematics Instructor and Artist

Mathematics Department, Western Washington University

Bellingham, Washington USA

So far my mathematical artwork has been about capturing some of my favorite mathematical ideas and trying to highlight the relationships present. What I'm most interested in now, is also getting math back out of the art, seeing relationships that I didn't notice before. I have a background in both mathematics and art, I practice them separately and together.

Prime Plaid

27 x 27 cm

Technical Pen on Bristol Board

2015

This piece is about patterns in primes and composites. To setup, we have a 48x48 grid that is numbered starting in the upper left corner. The primes are white, and the composites are shaded. It is similar to a Sieve of Erastosthenes, which finds prime numbers by first removing all the multiples of 2, then the multiples of 3, then the multiples of 5, and so forth. With only the numbers 2,3, and 5, we can find all the primes below 49. 7^2=49 is the first composite not eliminated by this sieve. Notice the pattern in the composites, 11313135153131…, it changes every time we hit a p^2 for prime p. The plaid is created with a twill weave of vertical and horizontal lines with lighter shading when there are five composites in a row.