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 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 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

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