A337415 a(n) is the number of ways to tile a size n triangle in the triangular grid with n n-cell polyiamonds, up to rotation and reflection of the triangle.

1, 0, 1, 3, 11, 314

Offset

1,4

Comments

The initial values are computed via the program from Arnauld Chevallier in the Code Golf Stack Exchange link.

Links

Table of n, a(n) for n=1..6.

Code Golf Stack Exchange, Cut a triangle into equal-sized parts!

Peter Kagey, Example of the a(5) = 11 partitions of the size 5 triangle into five 5-iamonds.

Example

An example of the a(4) = 3 essentially different ways of tiling a size 4 triangle with 4-iamonds can be found via the Code Golf Stack Exchange link.

Crossrefs

A328020 is the analog for square on the square grid.

Cf. A000577.

Sequence in context: A205771 A097423 A111130 * A264725 A088579 A344946

Adjacent sequences: A337412 A337413 A337414 * A337416 A337417 A337418

Keyword

nonn,more,hard

Author

Peter Kagey and Alec Jones, Aug 26 2020

Status

approved