cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-3 of 3 results.

A343577 Number of generalized polyforms on the truncated square tiling with n cells.

Original entry on oeis.org

1, 2, 2, 7, 22, 93, 413, 2073, 10741, 57540, 312805, 1722483, 9564565, 53489304, 300840332, 1700347858, 9650975401
Offset: 0

Views

Author

Peter Kagey, Apr 20 2021

Keywords

Comments

This sequence counts "free" polyforms where holes are allowed. This means that two polyforms are considered the same if one is a rigid transformation (translation, rotation, reflection or glide reflection) of the other.
a(n) >= A343417(n), the number of (n-k)-polyominoes with k distinguished vertices.

Crossrefs

Cf. A121197 (one-sided).
Analogous for other tilings: A000105 (square), A000228 (hexagonal), A000577 (triangular), A197156 (prismatic pentagonal), A197159 (floret pentagonal), A197459 (rhombille), A197462 (kisrhombille), A197465 (tetrakis square), A309159 (snub square), A343398 (trihexagonal), A343406 (truncated hexagonal).

Extensions

a(11) from Drake Thomas, May 02 2021
a(12)-a(16) from John Mason, Mar 20 2022

A121195 Consider the tiling of the plane with squares of two different sizes as in Fig. 2.4.2(g) of Grünbaum and Shephard, p. 74. a(n) is the number of connected figures that can be formed on this tiling, from n big squares and n small squares.

Original entry on oeis.org

1, 12, 152, 2538, 45084, 851717
Offset: 1

Views

Author

N. J. A. Sloane, Aug 17 2006

Keywords

Comments

The Zucca web site calls these figures "n-BiSquares".

References

  • Branko Grünbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987.

Crossrefs

Extensions

More terms from Don Reble, Aug 17 2007

A121196 Consider the tiling of the plane with squares of two different sizes as in Fig. 2.4.2(g) of Grünbaum and Shephard, p. 74. a(n) is the number of connected figures that can be formed on this tiling, from n tiles, each composed of a big square and an adjacent little square.

Original entry on oeis.org

1, 11, 114, 1519, 20769
Offset: 1

Views

Author

N. J. A. Sloane, Aug 17 2006

Keywords

Comments

The Zucca web site calls these figures "n-PairSquares".

References

  • Branko Grünbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987.

Crossrefs

Extensions

Better definition from Don Reble, Aug 17 2007
Showing 1-3 of 3 results.