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A221845
Number of prime dissections of an n X n square into integer-sided squares.
2
1, 1, 5, 38, 471, 10661, 450923, 35863932, 5353011030, 1500957421749, 790347882174803, 781621363452395224, 1451740730942350766747, 5064070747064013555843107, 33176273260130056822126522407
OFFSET
1,3
COMMENTS
A dissection into squares was called prime by J. H. Conway in 1964 if the GCD of the sides of the squares is 1.
REFERENCES
J. H. Conway, Mrs Perkins's quilt, Proc. Camb. Phil. Soc., 60 (1964), 363-368.
EXAMPLE
For n = 3 the a(3) = 5 dissections are:
+-+-+-+ +-+-+-+ +-+-+-+ +-+---+ +---+-+
| | | | | | | | | | | | | | | | | |
+-+-+-+ +-+-+-+ +-+-+-+ +-+ | | +-+
| | | | | | | | | | | | | | | |
+-+-+-+ +-+ | | +-+ +-+-+-+ +-+-+-+
| | | | | | | | | | | | | | | | | |
+-+-+-+ +-+---+ +---+-+ +-+-+-+ +-+-+-+
CROSSREFS
Sequence in context: A216858 A338867 A110467 * A299054 A095230 A247708
KEYWORD
nonn
AUTHOR
Geoffrey H. Morley, Jan 26 2013
EXTENSIONS
Corrected and extended to a(15) by Geoffrey H. Morley, Feb 05 2013
STATUS
approved