

A006983


Number of simple perfect squared squares of order n up to symmetry.
(Formerly M4482)


16



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
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OFFSET

1,22


COMMENTS

A squared rectangle (which may be a square) is a rectangle dissected into a finite number, two or more, of squares. If no two of these 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 mathematiques, BelinPour la Science, Paris, 2004, pp. 9596.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).


LINKS

Table of n, a(n) for n=1..35.
Stuart E. Anderson, Perfect Squared Rectangles and Squared Squares
Stuart E Anderson, Simple perfect squared squares in orders 27 to 35  methods used and people involved.
C. J. Bouwkamp, On some new simple perfect squared squares, Discrete Math. 106107 (1992) 6775.
C. J. Bouwkamp and A. J. W. Duijvestijn, Catalogue of Simple Perfect Squared Squares of orders 21 through 25, EUT Report 92WSK03, Eindhoven University of Technology, Eindhoven, The Netherlands, November 1992.
C. J. Bouwkamp and A. J. W. Duijvestijn, Album of Simple Perfect Squared Squares of order 26, EUT Report 94WSK02, Eindhoven University of Technology, Eindhoven, The Netherlands, December 1994.
G. Brinkmann and B. D. McKay, Fast generation of planar graphs, MATCH Commun. Math. Comput. Chem., 58 (2007), 323357.
G. Brinkmann and B. D. McKay, plantri and fullgen. [Programs for generation of certain types of planar graph.]
A. J. W. Duijvestijn, Illustration for a(21)=1 (The unique simple squared square of order 21. Reproduced with permission of the discoverer.)
A. J. W. Duijvestijn, Illustration for a(21)=1 (The unique simple squared square of order 21, better version. Reproduced with permission of the discoverer.)
A. J. W. Dujivestijn, Simple perfect squared squares and 2x1 squared rectangles of orders 21 to 24, J. Combin. Theory Ser. B 59 (1993), 2634.
A. J. W. Dujivestijn, Simple perfect squared squares and 2x1 squared rectangles of order 25, Math. Comp. 62 (1994), 325332. doi:10.1090/S00255718199412082209
A. J. W. Duijvestijn, Simple perfect squares and 2x1 squared rectangles of order 26, Math. Comp. 65 (1996), 13591364. doi:10.1090/S0025571896007053 [TableI List of Simple Perfect Squared Squares of order 26 and TableII List of Simple Perfect Squared 2x1 Rectangles of order 26 are now on squaring.net and no longer located as described in the paper.]
I. Gambini, Quant aux carres carreles, Thesis, Universite de la Mediterranee AixMarseille II, 1999, p. 25.
Eric Weisstein's World of Mathematics, Perfect Square Dissection
Index entries for squared squares


CROSSREFS

Cf. A002962, A002881, A002839, A014530.
Cf. A181340, A181735, A217155, A217156.
Sequence in context: A210982 A067677 A045523 * A072327 A218558 A181735
Adjacent sequences: A006980 A006981 A006982 * A006984 A006985 A006986


KEYWORD

nonn,hard,more,nice


AUTHOR

N. J. A. Sloane


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 cnets 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


STATUS

approved



