A385382 Number of polyominoes, i.e., connected nonempty subsets of square cells (or vertices), of the n X n flat torus, up to cyclic shifts and reflections of rows and columns.

1, 5, 28, 801, 129550

Offset

1,2

Links

Table of n, a(n) for n=1..5.

Pontus von Brömssen, Illustration for n = 3.

Crossrefs

Main diagonal of A385381.

Row sums of A385383.

Cf. A385384 (interchange of rows and columns of the torus allowed), A385387 (edge subsets).

Sequence in context: A249784 A359649 A346312 * A359739 A344464 A348393

Adjacent sequences: A385379 A385380 A385381 * A385383 A385384 A385385

Keyword

nonn,more

Author

Pontus von Brömssen, Jun 27 2025

Status

approved