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Search: id:A046747
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| A046747 |
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Number of n X n rational {0,1}-matrices of determinant 0. |
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+0 14
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| 1, 10, 338, 42976, 21040112, 39882864736, 292604283435872, 8286284310367538176
(list; graph; listen)
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OFFSET
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1,2
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REFERENCES
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J. Kahn, J. Komlos, E. Szemeredi: On the probability that a random $\pm1$-matrix is singular, J. AMS 8 (1995), 223-240.
J. Komlos, On the determinant of (0,1)-matrices, Studia Math. Hungarica 2 (1967), 7-21.
N. Metropolis and P. R. Stein, On a class of (0,1) matrices with vanishing determinants, J. Combin. Theory, 3 (1967), 191-198.
Miodrag Zivkovic, Classification of small (0,1) matrices, Linear Algebra and its Applications, 414 (2006), 310-346.
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LINKS
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Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.
M. Zivkovic, Classification of small (0,1) matrices, Linear Algebra and its Applications, 414 (2006), 310-346.
Index entries for sequences related to binary matrices
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FORMULA
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The probability that a random n X n {0,1}-matrix is singular is conjectured to be asymptotic to C(n+1, 2)*(1/2)^(n-1). [Corrected by njas, Jan 02 2007]
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EXAMPLE
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a(2)=10: the matrix of all 0's, 4 matrices with 2 zeros in the same row or column, 4 matrices with 3 zeros, and the all-1 matrix.
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PROGRAM
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(PARI) A046747(n) = m=matrix(n, n); ct=0; for(x=0, 2^(n*n)-1, a=binary(x+2^(n*n)); for(i=1, n, for(j=1, n, m[i, j]=a[n*i+j+1-n])); if(matdet(m)==0, ct=ct+1, ); ); ct - from Randall L. Rathbun
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CROSSREFS
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A046747(n) = 2^(n^2) - n! * binomial(2^n -1, n) + n! * A000410(n). Cf. A000409, A002884.
Cf. also A056990, A056989, A046747, A055165, A002416.
Also a(n) + A055165(n) = 2^(n^2) = total number of n X n (0, 1) matrices, sequence A002416.
Sequence in context: A064343 A127823 A113082 this_sequence A006426 A029698 A060704
Adjacent sequences: A046744 A046745 A046746 this_sequence A046748 A046749 A046750
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KEYWORD
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hard,nonn,nice
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AUTHOR
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G"unter M. Ziegler (ziegler(AT)math.tu-berlin.de)
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EXTENSIONS
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a(8) from Vladeta Jovovic (vladeta(AT)Eunet.yu), Mar 28 2006
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