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 1-10 of 15 results. Next

A224239 Number of inequivalent ways to cut an n X n square into squares with integer sides.

Original entry on oeis.org

1, 2, 3, 13, 77, 1494, 56978, 4495023, 669203528, 187623057932, 98793520541768, 97702673827558670
Offset: 1

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Author

N. J. A. Sloane, Apr 15 2013

Keywords

Comments

Similar to A045846, but now we do not regard dissections which differ by a rotation and/or reflection as distinct.

Examples

			For n=5, the illustrations (see links) show that the 77 solutions consist of:
4 dissections each with 1 image under the group of the square, for a total of 4,
2 dissections each with 2 images under the group of the square, totaling 4,
26 dissections each with 4 images under the group of the square, totaling 104, and
45 dissections each with 8 images under the group of the square, totaling 360,
for a grand total of 77 dissections with 472 images, agreeing with A045846(5) = 472.
		

Crossrefs

Main diagonal of A227690.

Extensions

a(6)-a(10) from Don Reble, Apr 15 2013
a(11)-a(12) from Ed Wynn, 2013. - N. J. A. Sloane, Nov 29 2013

A359019 Number of inequivalent tilings of a 3 X n rectangle using integer-sided square tiles.

Original entry on oeis.org

1, 1, 2, 3, 6, 10, 21, 39, 82, 163, 347, 717, 1533, 3232, 6927, 14748, 31645, 67690, 145322, 311535, 668997, 1435645, 3083301, 6619842, 14218066, 30533005, 65580338, 140847132, 302522253, 649759735, 1395611508, 2997573501, 6438470626, 13829057884, 29703388721, 63799607283, 137035047576, 294336860797, 632205714741
Offset: 0

Views

Author

John Mason, Dec 12 2022

Keywords

Examples

			a(4) is 6 because of:
  +-+-+-+ +-+-+-+ +-+-+-+ +-+-+-+ +-+-+-+ +-+-+-+
  | | | | |     | |   | | |   | | |   | | | | | |
  +-+-+-+ +     + +   +-+ +   +-+ +   +-+ +-+-+-+
  | | | | |     | |   | | |   | | |   | | |   | |
  +-+-+-+ +     + +-+-+-+ +-+-+-+ +-+-+-+ +   +-+
  | | | | |     | |   | | | |   | | | | | |   | |
  +-+-+-+ +-+-+-+ +   +-+ +-+   + +-+-+-+ +-+-+-+
  | | | | |     | |   | | | |   | | | | | | | | |
  +-+-+-+ +-+-+-+ +-+-+-+ +-+-+-+ +-+-+-+ +-+-+-+
		

Crossrefs

Column k = 3 of A227690.
Sequences for fixed and free (inequivalent) tilings of m X n rectangles, for 2 <= m <= 10:
Cf. A000930.

Formula

For n <= 1, a(n)=1;
otherwise for odd n > 1, a(n)=(A002478(n) + A000930(n) + 2 * A002478((n - 1) / 2) + 2 * A002478((n - 3) / 2)) / 4
and for even n, a(n)=(A002478(n) + A000930(n) + 2 * A002478((n - 2) / 2) + 2 * A002478(n / 2)) / 4
Alternatively, from Walter Trump:
For n <= 1, a(n)=1;
otherwise for odd n > 1, a(n)=(A000930(2n) + A000930(n) + 2 * A000930(n - 1) + 2 * A000930(n - 3)) / 4
and for even n, a(n)=(A000930(2n) + 2 * A000930(n - 2) + 3 * A000930(n)) / 4

A359020 Number of inequivalent tilings of a 4 X n rectangle using integer-sided square tiles.

Original entry on oeis.org

1, 1, 4, 6, 13, 39, 115, 295, 861, 2403, 7048, 20377, 60008, 175978, 519589, 1532455, 4531277, 13395656, 39639758, 117301153, 347248981, 1028011708, 3043852214, 9012879842, 26689014028, 79033362580, 234045889421, 693101137571, 2052569508948
Offset: 0

Views

Author

John Mason, Dec 12 2022

Keywords

Examples

			a(3) is 6 because of:
  +-+-+-+ +-+-+-+ +-+-+-+ +-+-+-+ +-+-+-+ +-+-+-+
  | | | | |     | |   | | |   | | |   | | | | | |
  +-+-+-+ +     + +   +-+ +   +-+ +   +-+ +-+-+-+
  | | | | |     | |   | | |   | | |   | | |   | |
  +-+-+-+ +     + +-+-+-+ +-+-+-+ +-+-+-+ +   +-+
  | | | | |     | |   | | | |   | | | | | |   | |
  +-+-+-+ +-+-+-+ +   +-+ +-+   + +-+-+-+ +-+-+-+
  | | | | |     | |   | | | |   | | | | | | | | |
  +-+-+-+ +-+-+-+ +-+-+-+ +-+-+-+ +-+-+-+ +-+-+-+
		

Crossrefs

Column k = 4 of A227690.
Sequences for fixed and free (inequivalent) tilings of m X n rectangles, for 2 <= m <= 10:

Formula

For even n > 4
a(n) = (A054856(n) + compo(n) + 4 * A054856((n - 2) / 2) +
2 * A054856((n - 4) / 2) + 2 * A054856(n / 2) +
2 * Sum_{k=0..(n - 2) / 2} (A054856(k))) / 4
For odd n > 4
a(n) = (A054856(n) + compo(n) + 2 * A054856((n - 3) / 2) +
2 * A054856((n - 1) / 2) + 2 * Sum_ {k=0..(n - 3) / 2} (A054856(k))) / 4
Where compo(n) is the number of distinct compositions of n as a sum of 1, 2, (1+1) and 4.

A359021 Number of inequivalent tilings of a 5 X n rectangle using integer-sided square tiles.

Original entry on oeis.org

1, 1, 5, 10, 39, 77, 521, 1985, 8038, 32097, 130125, 525676, 2131557, 8635656, 35017970, 141968455, 575692056, 2334344849, 9465939422, 38384559168, 155652202456, 631178976378, 2559476952229, 10378857744374, 42087027204278, 170665938023137, 692062856184512
Offset: 0

Views

Author

John Mason, Dec 12 2022

Keywords

Examples

			a(2) is 5 because of:
  +-+-+ +-+-+ +-+-+ +-+-+ +-+-+
  | | | |   | |   | |   | |   |
  +-+-+ +-+-+ +   + +   + +-+-+
  | | | |   | |   | |   | |   |
  +-+-+ +   + +-+-+ +-+-+ +   +
  | | | |   | |   | | | | |   |
  +-+-+ +-+-+ +-+-+ +-+-+ +-+-+
  | | | |   | |   | | | | | | |
  +-+-+ +   + +   + +-+-+ +-+-+
  | | | |   | |   | | | | | | |
  +-+-+ +-+-+ +-+-+ +-+-+ +-+-+
		

Crossrefs

Column k = 5 of A227690.
Sequences for fixed and free (inequivalent) tilings of m X n rectangles, for 2 <= m <= 10:
Cf. A079975.

Formula

For even n > 5:
a(n) = (A054857(n) + A079975(n) + 2*A054857(n/2) + 2* fixed_md(n/2) + 2*A054857((n-4)/2) + 4*A054857((n-2)/2) + 2* (A054857((n/2)-1) + fixed_md((n/2)-1)))/4.
For odd n > 5:
a(n) = (A054857(n) + A079975(n) + 2*A054857((n-1)/2) + 4*A054857((n-3)/2) + 2*fixed_md((n-3)/2) + 2*A054857((n-5)/2) + 2*fixed_md((n-1)/2))/4.
where
fixed_md(1)=1, fixed_md(2)=3, fixed_md(3)=15 and for n > 3, fixed_md(n) = A054857(n-1) + A054857(n-2) + fixed_md(n-2)+ fixed_md(n-1) + 2*A054857(n-3) + fixed_md(n-3).

A359022 Number of inequivalent tilings of a 6 X n rectangle using integer-sided square tiles.

Original entry on oeis.org

1, 1, 9, 21, 115, 521, 1494, 15129, 83609, 459957, 2551794, 14150081, 78597739
Offset: 0

Views

Author

John Mason, Dec 12 2022

Keywords

Crossrefs

Column k = 6 of A227690.
Sequences for fixed and free (inequivalent) tilings of m X n rectangles, for 2 <= m <= 10:

A359023 Number of inequivalent tilings of a 7 X n rectangle using integer-sided square tiles.

Original entry on oeis.org

1, 1, 12, 39, 295, 1985, 15129, 56978, 861159, 6542578, 49828415
Offset: 0

Views

Author

John Mason, Dec 12 2022

Keywords

Crossrefs

Column k = 7 of A227690.
Sequences for fixed and free (inequivalent) tilings of m X n rectangles, for 2 <= m <= 10:

A359024 Number of inequivalent tilings of an 8 X n rectangle using integer-sided square tiles.

Original entry on oeis.org

1, 1, 21, 82, 861, 8038, 83609, 861159, 4495023
Offset: 0

Views

Author

John Mason, Dec 12 2022

Keywords

Crossrefs

Column k = 8 of A227690.
Sequences for fixed and free (inequivalent) tilings of m X n rectangles, for 2 <= m <= 10:

A359025 Number of inequivalent tilings of a 9 X n rectangle using integer-sided square tiles.

Original entry on oeis.org

1, 1, 30, 163, 2403, 32097, 459957, 6542578, 93604244
Offset: 0

Views

Author

John Mason, Dec 12 2022

Keywords

Crossrefs

Column k = 9 of A227690.
Sequences for fixed and free (inequivalent) tilings of m X n rectangles, for 2 <= m <= 10:

A359026 Number of inequivalent tilings of a 10 X n rectangle using integer-sided square tiles.

Original entry on oeis.org

1, 1, 51, 347, 7048, 130125, 2551794, 49828415
Offset: 0

Views

Author

John Mason, Dec 12 2022

Keywords

Crossrefs

Column k = 10 of A227690.
Sequences for fixed and free (inequivalent) tilings of m X n rectangles, for 2 <= m <= 10:

A362258 Triangle read by rows: T(n,k) is the maximum number of ways in which a set of integer-sided squares can tile an n X k rectangle, up to rotations and reflections, 0 <= k <= n.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 4, 1, 1, 2, 4, 13, 20, 1, 1, 4, 8, 33, 125, 277, 1, 1, 6, 12, 72, 403, 2505, 7855, 1, 1, 9, 22, 204, 1438, 12069, 101587, 487662
Offset: 0

Views

Author

Pontus von Brömssen, Apr 15 2023

Keywords

Examples

			Triangle begins:
  n\k| 0  1  2  3   4    5     6      7      8
  ---+----------------------------------------
  0  | 1
  1  | 1  1
  2  | 1  1  1
  3  | 1  1  1  1
  4  | 1  1  2  2   4
  5  | 1  1  2  4  13   20
  6  | 1  1  4  8  33  125   277
  7  | 1  1  6 12  72  403  2505   7855
  8  | 1  1  9 22 204 1438 12069 101587 487662
See A362142 for an illustration of T(5,4) = 13.
The following table shows which sets of squares can tile the n X k rectangle in T(n,k) ways. A list x_1, ..., x_j represents a set of x_1 squares of side 1, ..., x_j squares of side j. When there are multiple solutions they are shown on separate lines. For (n,k) = (4,3), for example, the maximum number T(4,3) = 2 of tilings is obtained both for the set of 8 squares of side 1 and 1 square of side 2, and for the set of 4 squares of side 1 and 2 squares of side 2.
  n\k| 1   2      3     4     5     6      7       8
  ---+------------------------------------------------
  1  | 1
  2  | 2  4
     |    0,1
  3  | 3  6     9
     |    2,1   5,1
     |          0,0,1
  4  | 4  4,1   8,1    8,2
     |          4,2
  5  | 5  6,1   7,2   12,2  13,3
     |    2,2
  6  | 6  4,2  10,2   12,3  14,4  20,4
  7  | 7  6,2  13,2   12,4  19,4  22,5  25,6
  8  | 8  8,2  12,3   16,4  20,5  24,6  23,6,1  27,7,1
		

Crossrefs

Main diagonal: A362259.
Columns: A000012 (k = 0,1), A362260 (k = 2), A362261 (k = 3), A362262 (k = 4), A362263 (k = 5).
Cf. A227690, A361221 (rectangular pieces), A362142.

Formula

T(n,k) >= A362142(n,k)/4 if n != k.
T(n,n) >= A362142(n,n)/8.
Showing 1-10 of 15 results. Next