Tetraming Tri-Oddities
Introduction
A tetraming is a plane figure formed by joining four
cells in the equilateral triangular grid along edges or at corners or both.
There are 75 tetramings, including the three
tetriamonds, independent of reflection.
A tri-oddity
is a figure with ternary symmetry formed by joining a number of copies of
a polyform not a multiple of 3.
Here are the minimal known tetraming tri-oddities.
Please write if you find a smaller solution or solve an unsolved case.
See also Triming Tri-Oddities.
1 Tile
4 Tiles
7 Tiles
10 Tiles
13 Tiles
16 Tiles
19 Tiles
22 Tiles
25 Tiles
28 Tiles
31 Tiles
Impossible
No tetraming with an equal number of Δ and ∇ cells
can form a tri-oddity.
Unsolved
Last revised 2026-10-17.
Back to Polyiamond and Polyming Oddities
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Polyform Curiosities
Col. George Sicherman
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