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A220164
Number of simple squared squares of order n up to symmetry.
0
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 3, 5, 15, 19, 57, 72, 275, 499, 1778, 3705, 11318, 24525, 65906, 135599, 333938, 687969, 1681759, 3652677
OFFSET
1,15
COMMENTS
A squared rectangle is a rectangle dissected into a finite number, two or more, of squares, called the elements of the dissection. If no two of these squares have the same size the squared rectangle is called perfect, otherwise it is imperfect. The order of a squared rectangle is the number of constituent squares. The case in which the squared rectangle is itself a square is called a squared square. The dissection is simple if it contains no smaller squared rectangle, otherwise it is compound. This sequence counts both perfect and imperfect simple squared squares up to symmetry.
REFERENCES
See A006983 and A217156.
LINKS
S. E. Anderson, Mrs Perkins's Quilts
Eric Weisstein's World of Mathematics, Perfect Square Dissection
FORMULA
a(n) = A006983(n) + A002962(n).
CROSSREFS
KEYWORD
nonn,hard
AUTHOR
Stuart E Anderson, Dec 06 2012
EXTENSIONS
a(13)-a(29) from Stuart E Anderson, Dec 07 2012
Clarified some definitions in comments and added a(30) - Stuart E Anderson, Jun 03 2013
a(31), a(32) added by Stuart E Anderson, Sep 30 2013
STATUS
approved