\(1 + 3 + 5 + . . . + (2N -1) = N^2\) and \(2 + 4 + 6 + 8 + . . . + 2N = N(N - 1)\)
Designer and Artist: Jean MacGregor Horn
Material and Method: Counted Cross-stitch on #14 Aida Cloth
Year of Creation: Stitched in 2017
The left-hand cross-stitch gives a visual proof of the summation of the series \(1 + 3 + 5 + . . . + (2N - 1) = N^2\) .
The right-hand cross-stitch gives a geometric representation of the summation of the series \(2 + 4 + 6 + 8 + . . . + 2N = N(N-1)\).