T-shirt and poster details below.
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Featuring Neil Sloane from the OEIS: https://oeis.org
And thanks to Jonathan Wild: https://www.mcgill.ca/music/jonathan-wild
OEIS A250001 - Number of arrangements of n circles in the affine plane: https://oeis.org/A250001
3-Circles T-Shirt: https://teespring.com/three-circles-numberphile
4-Circles Poster: https://teespring.com/four-circles-numberphile
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