A057782 Building block is trapezoid formed from 3 equilateral triangles; sequence gives number of pieces (polytraps) that can be formed from n such trapezoids.

1, 9, 94, 1552, 27285, 509805, 9783124

Offset: 1

Author

N. J. A. Sloane, Oct 29 2000

Keywords

• nonn
• nice
• hard
• more

Comments

Also known as "Polytriamonds" because the building block is the unique triamond (composite of three equilateral triangles joined edge-to-edge). - Aaron N. Siegel, May 23 2022

References

• Computed by Brendan Owen.

Links

• Abaroth's World, Polyhes, Polyhalfhexes & Polytriamonds
• Andrew Clarke, Other Polyforms

Crossrefs

Cf. A000577, A000228, A000105, A056844.

Extensions

Link updated by William Rex Marshall, Dec 16 2009

a(7) from Aaron N. Siegel, May 23 2022