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.

A276523 Partition an n X n square into multiple non-congruent integer-sided rectangles. a(n) is the least possible difference between the largest and smallest area.

Original entry on oeis.org

2, 4, 4, 5, 5, 6, 6, 8, 6, 7, 8, 6, 8, 8, 8, 8, 8, 9, 9, 9, 8, 9, 10, 9, 10, 9, 9, 11, 11, 10, 12, 12, 11, 12, 11, 10, 11, 12, 13, 12, 12, 12, 13, 13, 12, 14, 12, 13, 14, 13, 14, 15, 14, 14, 15, 15, 14, 15, 15, 14, 15, 15, 15
Offset: 3

Views

Author

Ed Pegg Jr, Nov 15 2016

Keywords

Comments

Developed as the Mondrian Art Puzzle.
The rectangles can be similar, though. - Daniel Forgues, Nov 22 2016
That is, there can be a 1x2 rectangle and a 2x4 rectangle (these are similar), but there can't be two 1x2 rectangles (these are congruent). - Michael B. Porter, Oct 13 2018
Upper bounds for a(n) are n if n is odd, and min(2*n, 4 * a(n/2)) if n is even. - Roderick MacPhee, Nov 28 2016
An upper bound seems to be ceiling(n/log(n))+3, or A050501+3. See A278970. Holds to at least a(96). - Ed Pegg Jr, Dec 02 2016
Best known values for a(66)-a(96) as follows: 16, 18, 19, 18, 19, 18, 20, 20, 20, 20, 19, 20, 21, 21, 20, 21, 20, 20, 21, 22, 18, 22, 20, 22, 24, 23, 22, 22, 24, 24, 24. - (shortened by Ruud H.G. van Tol, Oct 25 2024)

Examples

			A size-11 square can be divided into 3 X 4, 2 X 6, 2 X 7, 3 X 5, 4 X 4, 2 X 8, 2 X 9, and 3 X 6 rectangles. 18 - 12 = 6, the minimal area range.
The 14 X 14 square can be divided into non-congruent rectangles of area 30 to 36:
  aaaaaaaaaabbbb
  aaaaaaaaaabbbb
  aaaaaaaaaabbbb
  cccdddddddbbbb
  cccdddddddbbbb
  cccdddddddbbbb
  cccdddddddbbbb
  cccdddddddbbbb
  ccceeeeeffffff
  ccceeeeeffffff
  ccceeeeeffffff
  ccceeeeeffffff
  ccceeeeeffffff
  ccceeeeeffffff
		

Crossrefs

Extensions

Bruce Norskog corrected a(18), and a recheck by Pegg corrected a(15) and a(19). - Charles R Greathouse IV, Nov 28 2016
Correction of a(14), a(16), a(23) and new terms a(25)-a(28) from Robert Gerbicz, Nov 28 2016
a(29)-a(44) from Robert Gerbicz, Dec 02 2016
a(45)-a(47) from Robert Gerbicz added, as well as best known values to a(96).
Correction of a(45), a(46) and new terms a(48)-a(57) from Robert Gerbicz, Dec 27 2016
a(58)-a(65) from Michel Gaillard, Oct 23 2020

A279596 Partition an n X n square into multiple integer-sided rectangles where no one is a translation of any other; a(n) is the least possible difference between the largest and smallest area.

Original entry on oeis.org

2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5, 6, 6, 4, 6, 6, 6, 6, 6, 6, 7, 7, 7, 8, 7, 6, 6, 8, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9
Offset: 3

Views

Author

Ed Pegg Jr, Dec 15 2016

Keywords

Comments

Similar to the Mondrian Art sequence (A276523), but allowing repetition of rectangles with different orientations.
Proved optimal to a(45) by R. Gerbicz. Best values known for a(46)-a(96): 10, 12, 11, 12, 12, 8, 12, 12, 13, 12, 12, 14, 14, 15, 12, 15, 14, 15, 14, 16, 16, 15, 16, 16, 16, 17, 16, 17, 14, 17, 18, 16, 18, 16, 18, 15, 16, 18, 18, 16, 18, 17, 19, 20, 17, 17, 21, 20, 20, 21, 22.
Seems to be bounded above by ceiling(n/log(n)). The currently verified distances from this bound are 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 2, 1, 1, 2, 1, 1, 3, 1, 2, 2, 2, 2, 2, 2 (A279848).

Examples

			The 9 X 9 square can be divided into non-translatable rectangles with
aaaaaaaab
ddddddeeb
fggghheeb
fggghheeb
fiiihheeb
fiiijjjjb
fiiijjjjb
fkkkkkkkb
ccccccccc
		

Crossrefs

Extensions

Moved terms to A279848, expanded best values known
a(28)-a(45) from Robert Gerbicz, Jan 01 2017

A279848 Partition an n X n square into multiple integer-sided rectangles where no one is a translation of any other. a(n) is ceiling(n/log(n)) - the least possible difference between the largest and smallest area.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 2, 1, 1, 2, 1, 1, 3, 1, 2, 2, 2, 2, 2, 2, 2, 2, 1, 3, 4, 4, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 3
Offset: 3

Views

Author

Ed Pegg Jr, Dec 21 2016

Keywords

Comments

If ceiling(n/log(n)) is an upper bound for the Mondrian Art Problem variant (A279596), a(n) is the amount by which the optimal value beats the upper bound.
Terms a(3) to a(45) verified optimal by R. Gerbicz.
Term a(103) is at least 9, defect 14 (630-616) with 17 rectangles.
Best values known for a(46) to a(96): 3, 1, 2, 1, 1, 5, 2, 2, 1, 2, 2, 1, 1, 0, 3, 0, 2, 1, 2, 0, 0, 1, 1, 1, 1, 0, 1, 1, 4, 1, 0, 2, 0, 3, 1, 4, 3, 1, 1, 4, 2, 3, 1, 0, 4, 4, 0, 1, 1, 0, 0.

Crossrefs

Extensions

a(28)-a(45) from Robert Gerbicz, Jan 01 2017
Showing 1-3 of 3 results.