A046747 Number of n X n rational {0,1}-matrices of determinant 0.

1, 10, 338, 42976, 21040112, 39882864736, 292604283435872, 8286284310367538176

Offset

1,2

Links

Table of n, a(n) for n=1..8.

J. Bourgain, V. Vu and P. M. Wood, On the Singularity Probability of Discrete Random Matrices, Journal of Functional Analysis, 258 (2010), 559-603.

R. P. Brent and J. H. Osborn, Bounds on minors of binary matrices, arXiv preprint arXiv:1208.3330 [math.CO], 2012.

J. Kahn, J. Komlos and E. Szemeredi, On the probability that a random ±1-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.

Eric Weisstein's World of Mathematics, Singular Matrix.

Miodrag Zivkovic, Classification of small (0,1) matrices, arXiv:math/0511636 [math.CO], 2005.

Miodrag Zivkovic, Classification of small (0,1) matrices, Linear Algebra and its Applications, 414 (2006), 310-346.

Index entries for sequences related to binary matrices

Formula

a(n) = 2^(n^2) - n! * binomial(2^n -1, n) + n! * A000410(n).

a(n) + A055165(n) = 2^(n^2) = total number of n X n (0, 1) matrices.

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 N. J. A. Sloane, Jan 02 2007]

Example

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.

Mathematica

Sum[KroneckerDelta[Det[Array[Mod[Floor[k/(2^(n*(#1-1)+#2-1))], 2]&, {n, n}]], 0], {k, 0, (2^(n^2))-1}] (* John M. Campbell, Jun 24 2011 *)

Prog

(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 \\ Randall L Rathbun
(PARI) a(n)=sum(i=0, 2^n^2-1, matdet(matrix(n, n, x, y, (i>>(n*x+y-n-1))%2))==0) \\ Charles R Greathouse IV, Feb 21 2015

Crossrefs

Cf. A000409, A000410, A002416, A002884, A046747, A055165, A056989, A056990.

Sequence in context: A352798 A113082 A288684 * A338799 A006426 A029698

Adjacent sequences: A046744 A046745 A046746 * A046748 A046749 A046750

Keyword

hard,nonn,nice

Author

Günter M. Ziegler (ziegler(AT)math.tu-berlin.de)

Extensions

a(8) from Vladeta Jovovic, Mar 28 2006

Status

approved