A359068 Number of 1-sided strip polyominoes with n cells.

1, 1, 2, 5, 10, 24, 52, 124, 282, 668, 1548, 3654, 8533, 20093, 47033, 110533, 258807, 607227, 1421055, 3329585, 7785995, 18221563, 42575336, 99539106, 232398659, 542864111, 1266567155, 2956342341, 6893180336, 16078817198, 37469245219, 87347384305, 203447081205

Offset

1,3

Comments

A "strip" polyomino is a snake polyomino (A151514) with no holes.

This sequence first differs from A151514 at n = 7. An example of a polyomino counted by A151514, but not by this sequence, is:

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Links

Table of n, a(n) for n=1..33.

Arthur O'Dwyer, Polyomino strips, snakes, and ouroboroi (gives first 33 terms).

Arthur O'Dwyer, C++ program.

Prog

(C++) // see Links section

Crossrefs

A333313 gives the number of free (2-sided) strip polyominoes with n cells. Subtracting A333313 from A359068 gives the number of chiral pairs.

A151514 gives the number of 1-sided snake polyominoes with n cells; A151514(n) > A359068(n) for n >= 7.

Subtracting A359068 from A151514 gives the number of snake polyominoes with n cells that have at least one hole.

Sequence in context: A032170 A084081 A106376 * A151514 A321007 A253013

Adjacent sequences: A359065 A359066 A359067 * A359069 A359070 A359071

Keyword

nonn,more

Author

Arthur O'Dwyer, Jan 11 2023

Status

approved