The 6-polyiamond illustrated above.
Butterfly Polyiamond
See also
Butterfly Catastrophe, Butterfly Curve, Butterfly Effect, Butterfly Function, Butterfly Graph, Butterfly Lemma, Butterfly TheoremExplore with Wolfram|Alpha
References
Golomb, S. W. Polyominoes: Puzzles, Patterns, Problems, and Packings, 2nd ed. Princeton, NJ: Princeton University Press, p. 92, 1994.Referenced on Wolfram|Alpha
Butterfly PolyiamondCite this as:
Weisstein, Eric W. "Butterfly Polyiamond." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/ButterflyPolyiamond.html