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.

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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.
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