A320944 -id:A320944 - cp's OEIS frontend

1, 1, 3, 20, 268

Offset: 2

Bridget Tenner, Oct 24 2018

Also the number of bottom-perimeter tiles among all rhombic tilings of the 2n-gon. Tiles and polygons all have sides of length 1, as in A006245.

			a(4) = 3 because among the eight rhombic tilings of the octagon, 3 top-perimeter rhombi appear.

B. E. Tenner, Tiling-based models of perimeter and area, arXiv:1811.00082 [math.CO], 2018.

1, 2, 9, 80, 1340

Offset: 2

Bridget Tenner, Oct 24 2018

Also the number of right-perimeter tiles among all rhombic tilings of the 2n-gon. Tiles and polygons all have sides of length 1, as in A006245.

			a(4) = 9 because among the eight rhombic tilings of the octagon, 9 left-perimeter rhombi appear.

B. E. Tenner, Tiling-based models of perimeter and area, arXiv:1811.00082 [math.CO], 2018.

a(n) = (n-1) * A320945(n).

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