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 1-6 of 6 results.

A006983 Number of simple perfect squared squares of order n up to symmetry.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 8, 12, 26, 160, 441, 1152, 3001, 7901, 20566, 54541, 144161, 378197, 990981, 2578081, 6674067, 17086918
Offset: 1

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Keywords

Comments

A squared rectangle (which may be a square) is a rectangle dissected into a finite number of two or more squares. If no two squares have the same size, the squared rectangle is perfect. A squared rectangle is simple if it does not contain a smaller squared rectangle. The order of a squared rectangle is the number of constituent squares. - Geoffrey H. Morley, Oct 17 2012

References

  • J.-P. Delahaye, Les inattendus mathématiques, Belin-Pour la Science, Paris, 2004, pp. 95-96.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Cf. A129947, A217149, A228953 (related to sizes of the squares).
Cf. A349205, A349206, A349207, A349208, A349209, A349210 (related to ratios of element and square sizes).

Extensions

Leading term changed from 0 to 1, Apr 15 1996
More terms from Stuart E Anderson, May 08 2003, Nov 2010
Leading term changed back to 0, Dec 25 2010 (cf. A178688)
a(29) added by Stuart E Anderson, Aug 22 2010; contributors to a(29) include Ed Pegg Jr and Stephen Johnson
a(29) changed to 7901, identified a duplicate tiling in order 29. - Stuart E Anderson, Jan 07 2012
a(28) changed to 3000, identified a duplicate tiling in order 28. - Stuart E Anderson, Jan 14 2012
a(28) changed back to 3001 after a complete recount of order 28 SPSS recalculated from c-nets with cleansed data, established the correct total of 3001. - Stuart E Anderson, Jan 24 2012
Definition clarified by Geoffrey H. Morley, Oct 17 2012
a(30) added by Stuart E Anderson, Apr 10 2013
a(31), a(32) added by Stuart E Anderson, Sep 29 2013
a(33), a(34) and a(35) added by Stuart E Anderson, May 02 2016
Moved comments on orders 27 to 35 to a linked file. Stuart E Anderson, May 02 2016
a(36) and a(37) enumerated by Jim Williams, added by Stuart E Anderson, Jul 26 2020.

A349205 a(n) is the side length (size) of the smallest element in a simple perfect squared square of order n such that the ratio of the size of the smallest element to the total size of the square assumes a maximum over all possible A006983(n) dissections of order n.

Original entry on oeis.org

2, 4, 2, 3, 12, 17, 48, 29, 62, 53, 64, 156, 70, 270, 257, 333, 716
Offset: 21

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Author

Hugo Pfoertner, Nov 22 2021

Keywords

Examples

			See Pfoertner link.
		

Crossrefs

A349206 gives the corresponding total sizes of those squares that lead to the maximum ratio.

A349206 a(n) is the side length of the simple perfect squared square of order n leading to a maximum of the ratio of the side length of its smallest element A349205(n) to its total side length.

Original entry on oeis.org

112, 192, 140, 120, 381, 544, 1032, 732, 1615, 1485, 1408, 3584, 1625, 6808, 6192, 7743, 16581
Offset: 21

Views

Author

Hugo Pfoertner, Nov 22 2021

Keywords

Examples

			See A349205.
		

Crossrefs

A349207 a(n) is the side length (size) of the smallest element in a simple perfect squared square of order n such that the ratio of the size of the smallest element to the size of the largest element of the square assumes a maximum over all possible A006983(n) dissections of order n.

Original entry on oeis.org

2, 4, 2, 3, 16, 17, 48, 29, 62, 69, 64, 88, 70, 111, 355, 333, 543
Offset: 21

Views

Author

Hugo Pfoertner, Nov 22 2021

Keywords

Examples

			See Pfoertner link.
		

Crossrefs

A349208 gives the corresponding sizes of the largest elements that lead to the maximum ratio.

A349209 a(n) is the maximum of the side lengths of the smallest elements of all simple perfect squared squares of order n.

Original entry on oeis.org

2, 4, 2, 8, 16, 20, 48, 48, 69, 74, 107, 158, 177, 270, 355, 519, 716
Offset: 21

Views

Author

Hugo Pfoertner, Nov 17 2021

Keywords

Examples

			See linked illustrations.
		

Crossrefs

A349210 a(n) is the minimum of the side lengths of the largest elements of all simple perfect squared squares of order n.

Original entry on oeis.org

50, 55, 44, 47, 74, 78, 81, 77, 99, 77, 87, 80, 94, 79, 89, 96, 93
Offset: 21

Views

Author

Hugo Pfoertner, Nov 17 2021

Keywords

Examples

			See linked illustrations.
		

Crossrefs

Showing 1-6 of 6 results.