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A057982
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Number of singular n X n (-1,1)-matrices.
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1
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OFFSET
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1,2
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COMMENTS
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a(n) = 2^(2n-1)*A046747(n-1). - Kevin Costello, May 18 2005
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LINKS
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FORMULA
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a(n)/2^(n^2) ~ (1/2 + o_n(1))^n (proved by Tikhomirov). - Timothy Y. Chow, Jan 17 2019
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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More terms from Kevin Costello, May 18 2005
a(6)-a(9) from Herman Jamke (hermanjamke(AT)fastmail.fm), Apr 18 2008
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STATUS
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approved
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