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 A221845 Number of prime dissections of an n X n square into integer sided squares. 1
 1, 1, 5, 38, 471, 10661, 450923, 35863932, 5353011030, 1500957421749, 790347882174803, 781621363452395224, 1451740730942350766747, 5064070747064013555843107, 33176273260130056822126522407 (list; graph; refs; listen; history; text; internal format)
 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. LINKS Ed Wynn, Exhaustive generation of Mrs Perkins's quilt square dissections for low orders, arXiv:1308.5420 EXAMPLE For n = 3 the a(3) = 5 dissections are: +-+-+-+   +-+-+-+   +-+-+-+   +-+---+   +---+-+ | | | |   | | | |   | | | |   | |   |   |   | | +-+-+-+   +-+-+-+   +-+-+-+   +-+   |   |   +-+ | | | |   | |   |   |   | |   | |   |   |   | | +-+-+-+   +-+   |   |   +-+   +-+-+-+   +-+-+-+ | | | |   | |   |   |   | |   | | | |   | | | | +-+-+-+   +-+---+   +---+-+   +-+-+-+   +-+-+-+ CROSSREFS Cf. A045846, A221844. Sequence in context: A069471 A216858 A110467 * A299054 A095230 A247708 Adjacent sequences:  A221842 A221843 A221844 * A221846 A221847 A221848 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

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Last modified October 23 05:56 EDT 2019. Contains 328335 sequences. (Running on oeis4.)