### \(1 + 3 + 5 + . . . + (2N -1) = N^2\) 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 \(2 + 4 + 6 + 8 + . . . + 2N = N(N-1)\).