login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A195984 The size of the smallest boundary square in simple perfect squared rectangles of order n. 0
8, 13, 22, 18, 14, 13, 11, 9, 6, 9, 7, 7, 8, 6, 8, 7 (list; graph; refs; listen; history; text; internal format)
OFFSET

9,1

COMMENTS

Ian Gambini showed in his thesis that the minimum value for a(n) is 5. Brian Trial found 3 simple perfect squared rectangles (SPSRs) of order 28 with boundary squares of size 5 in September 2011. An unsolved problem is to find the lowest order SPSR with a '5 on the side'.

Added a(22) = 6 (Stuart Anderson), Brian Trial has found a(28) = 5. This gives an upper bound of 28, in addition to the lower bound of 23, to the problem of finding the lowest order SPSR with a square of size 5 on the boundary. - Stuart E Anderson, Sep 29 2011

Found a(23) = 8, the lower bound is now order 24. - Stuart E Anderson, Nov 30 2012

Found a(24) = 7, the lower bound is now order 25. - Stuart E Anderson, Dec 07 2012

REFERENCES

Gambini, Ian. Thesis; 'Quant aux carrés carrelés' L’Universite de la Mediterranee Aix-Marseille II 1999

LINKS

Table of n, a(n) for n=9..24.

Stuart E. Anderson, Simple Perfects by Boundary Rules and Conditions

Stuart Anderson, 'Special' Perfect Squared Squares", accessed 2014. - N. J. A. Sloane, Mar 30 2014

CROSSREFS

Cf. A002839.

Sequence in context: A273980 A101642 A269354 * A019535 A229446 A205704

Adjacent sequences:  A195981 A195982 A195983 * A195985 A195986 A195987

KEYWORD

nonn

AUTHOR

Stuart E Anderson, Sep 26 2011

EXTENSIONS

Added a(23) = 8, Stuart E Anderson, Nov 30 2012

Added a(24) = 7, Stuart E Anderson, Dec 07 2012

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified July 26 06:03 EDT 2017. Contains 289798 sequences.