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.

Previous Showing 11-16 of 16 results.

A360498 Number of ways to tile an n X n square using oblongs with distinct dimensions.

Original entry on oeis.org

0, 0, 4, 12, 256, 3620, 87216, 2444084, 87181220
Offset: 1

Views

Author

Scott R. Shannon, Feb 09 2023

Keywords

Comments

All possible tilings are counted, including those identical by symmetry. Note that distinct dimensions means that, for example, a 1 x 3 oblong can only be used once, regardless of if it lies horizontally or vertically.

Examples

			a(1) = 0 as no distinct oblongs can tile a square with dimensions 1 x 1.
a(2) = 0 as no distinct oblongs can tile a square with dimensions 2 x 2.
a(3) = 4. There is one tiling, excluding those equivalent by symmetry:
.
  +---+---+---+
  |           |
  +---+---+---+
  |           |
  +           +
  |           |
  +---+---+---+
.
This tiling can occur in 4 different ways, giving 4 ways in total.
a(4) = 12. The possible tilings, excluding those equivalent by symmetry, are:
.
  +---+---+---+---+   +---+---+---+---+
  |   |           |   |               |
  +   +           +   +---+---+---+---+
  |   |           |   |               |
  +---+---+---+---+   +               +
  |               |   |               |
  +               +   +               +
  |               |   |               |
  +---+---+---+---+   +---+---+---+---+
.
The first tiling can occur in 8 different way and the second in 4 different ways, giving 12 ways in total.
		

Crossrefs

Cf. A360499 (rectangles), A004003, A099390, A065072, A233320, A230031.

A233339 Number of tilings of a 4 X 3n rectangle using 4n trominoes of any shape.

Original entry on oeis.org

1, 23, 939, 41813, 1895145, 86208957, 3924499731, 178682349823, 8135650498647, 370429531112741, 16866286184557689, 767950873073579951, 34966119230441665595, 1592067343861413081837, 72489555274710984629691, 3300573714050654978094583, 150280779093325614402294089
Offset: 0

Views

Author

Alois P. Heinz, Dec 07 2013

Keywords

Crossrefs

Trisection of column k=4 of A233320.

Formula

G.f.: (-x^14 +45*x^13 -790*x^12 +7195*x^11 -37791*x^10 +120544*x^9 -241021*x^8 +307384*x^7 -251359*x^6 +131039*x^5 -42817*x^4 +8472*x^3 -952*x^2 +53*x -1) / (x^15 -56*x^14 +1223*x^13 -13643*x^12 +87066*x^11 -338409*x^10 +836269*x^9 -1345297*x^8 +1419177*x^7 -976456*x^6 +431092*x^5 -118633*x^4 +19424*x^3 -1761*x^2 +76*x -1).

A233340 Number of tilings of a 5 X 3n rectangle using 5n trominoes of any shape.

Original entry on oeis.org

1, 62, 8342, 1269900, 198253934, 31111319376, 4887323351972, 767919868804309, 120664440361104580, 18960353496615710993, 2979300461790704311162, 468147088780110777732830, 73561466714064126023807694, 11558951424929920406557632356, 1816295465197137076501207582877
Offset: 0

Views

Author

Alois P. Heinz, Dec 07 2013

Keywords

Crossrefs

Trisection of column k=5 of A233320.

Formula

G.f.: see link above.

A233343 Number of tilings of a 7 X 3n rectangle using 7n trominoes of any shape.

Original entry on oeis.org

1, 441, 614581, 1064557805, 1949314526229, 3619365754064658, 6743148875847013949, 12573396789552627635974, 23449283563696481324707977, 43734844458505039459034141789, 81570040233489554572733439665568, 152137050633841639720340771054558899
Offset: 0

Views

Author

Alois P. Heinz, Dec 07 2013

Keywords

Crossrefs

Trisection of column k=7 of A233320.

A269958 Number of tilings of an 8 X 3n rectangle using 8n trominoes of any shape.

Original entry on oeis.org

1, 1173, 5271923, 30860212081, 193553900967497, 1235348565576072999, 7918615596845276941783, 50812059004074711375396005, 326133836808482000144440191279, 2093399184722452211913343015136793, 13437387174568575272118729720355720407
Offset: 0

Views

Author

Alois P. Heinz, Mar 08 2016

Keywords

Crossrefs

Trisection of column k=8 of A233320.

A269959 Number of tilings of a 10 X 3n rectangle using 10n trominoes of any shape.

Original entry on oeis.org

1, 8266, 379419508, 25020222581494, 1830607857363940042, 137787968143635937039786, 10448677822353537147395706384, 793868918375370204415242288244707, 60346488218332294539638857492286577712, 4587865445075128062280066720936757293474915
Offset: 0

Views

Author

Alois P. Heinz, Mar 08 2016

Keywords

Crossrefs

Trisection of column k=10 of A233320.
Previous Showing 11-16 of 16 results.