A390124 The number of free polygems with n cells.

1, 1, 4, 15, 78, 450, 2876, 18792

Offset

0,3

Comments

A polygem is a third of a regular hexagon where there are two edges from the center of the hexagons to the midpoints of a side which form a 120 degree angle with each other.

Links

Table of n, a(n) for n=0..7.

Abaroth, Polygems (via Internet Archive).

George Sicherman, Polygem Oddities.

Crossrefs

Cf. A000105 (square), A000228 (hexagonal), A000577 (triangular), A197156 (prismatic pentagonal), A197159 (floret pentagonal), A197459 (rhombille), A197462 (kisrhombille), A197465 (tetrakis square), A309159 (snub square), A343398 (trihexagonal), A343406 (truncated hexagonal), A343577 (truncated square), A344211 (rhombitrihexagonal), A344213 (truncated trihexagonal), A383908 (snub trihexagonal), A385265 (pinwheel), A385266 (basketweave).

Sequence in context: A243327 A179511 A111726 * A090376 A232042 A125307

Adjacent sequences: A390121 A390122 A390123 * A390125 A390126 A390127

Keyword

nonn,more

Author

Peter Kagey, Jan 18 2026

Status

approved