A055165
Number of invertible n X n matrices with entries equal to 0 or 1.
Original entry on oeis.org
1, 1, 6, 174, 22560, 12514320, 28836612000, 270345669985440, 10160459763342013440
Offset: 0
Ulrich Hermisson (uhermiss(AT)server1.rz.uni-leipzig.de), Jun 18 2000
For n=2 the 6 matrices are {{{0, 1}, {1, 0}}, {{0, 1}, {1, 1}}, {{1, 0}, {0, 1}}, {{1, 0}, {1, 1}}, {{1, 1}, {0, 1}}, {{1, 1}, {1, 0}}}.
- Eric Weisstein's World of Mathematics, Nonsingular Matrix.
- Chai Wah Wu, Can machine learning identify interesting mathematics? An exploration using empirically observed laws, arXiv:1805.07431 [cs.LG], 2018.
- Miodrag Zivkovic, Classification of small (0,1) matrices, arXiv:math/0511636 [math.CO], 2005; Linear Algebra and its Applications, 414 (2006), 310-346.
- Miodrag Zivkovic, Classification of (0,1) matrices of order not exceeding 8.
- Index entries for sequences related to binary matrices
A046747(n) + a(n) = 2^(n^2) = total number of n X n (0, 1) matrices = sequence
A002416.
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a(n)=sum(t=0,2^n^2-1,!!matdet(matrix(n,n,i,j,(t>>(i*n+j-n-1))%2))) \\ Charles R Greathouse IV, Feb 09 2016
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from itertools import product
from sympy import Matrix
def A055165(n): return sum(1 for s in product([0,1],repeat=n**2) if Matrix(n,n,s).det() != 0) # Chai Wah Wu, Sep 24 2021
More terms from Miodrag Zivkovic (ezivkovm(AT)matf.bg.ac.rs), Feb 28 2006
A000410
Number of singular n X n rational (0,1)-matrices.
Original entry on oeis.org
0, 0, 6, 425, 65625, 27894671, 35716401889, 144866174953833
Offset: 1
- N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
- N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
- 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, 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
n=7 term from Guenter M. Ziegler (ziegler(AT)math.TU-Berlin.DE)
A064231
Triangle read by rows: T(n,k) = number of rational (+1,-1) matrices of rank k (n >= 1, 1 <= k <= n).
Original entry on oeis.org
2, 8, 8, 32, 288, 192, 128, 6272, 36864, 22272, 512, 115200, 3456000, 18432000, 11550720, 2048, 1968128, 243302400, 6471168000, 36373708800, 25629327360, 8192, 32514048, 14809546752, 1557061632000, 43378316083200, 281770208133120
Offset: 1
2; 8,8; 32,288,192; 128,6272,36864,22272; ...
- 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 determinants of random matrices, Studia Sci. Math. Hungar., 3 (1968), 387-399.
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T=matrix(4,4); { for(n=1,4, mm=matrix(n,n); for(k=1,n, T[n,k]=0); forvec(x=vector(n*n,i,[0,1]), for(i=1,n, for(j=1,n,mm[i,j]=(-1)^x[i+n*(j-1)])); T[n,matrank(mm)]++); for(k=1,n,print1(T[n,k], if(k
Offset changed to 1 by
T. D. Noe, Mar 02 2011
A086875
Sum of rank(M) over all n X n matrices over Z with all entries zero or one.
Original entry on oeis.org
1, 21, 1147, 211965, 143331811, 366753209781
Offset: 1
Tom Womack (tom(AT)womack.net), Aug 21 2003
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for a in [1..5] do b := 0; for c in CartesianPower([0,1], a^2) do b +:= Rank(Matrix(a, a, [aa : aa in c])); end for; print b; end for;
A354741
Triangular array read by rows. T(n,k) is the number of n X n Boolean matrices with row rank k, n >= 0, 0 <= k <= n.
Original entry on oeis.org
1, 1, 1, 1, 9, 6, 1, 49, 306, 156, 1, 225, 8550, 37488, 19272, 1, 961, 194850, 4811700, 17551800, 10995120
Offset: 0
Table begins:
1;
1, 1;
1, 9, 6;
1, 49, 306, 156;
1, 225, 8550, 37488, 19272;
...
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Table[B = Tuples[Tuples[{0, 1}, nn],nn]; bospan[matrix_]:= Sort[DeleteDuplicates[
Map[Clip[Total[#]] &, Drop[Subsets[matrix], 1]]]]; rowrank[matrix_] :=
If[Total[Map[Total, matrix]] == 0, 0, Length[Select[Drop[Subsets[DeleteCases[matrix, Table[0, {nn}]]], 1],
bospan[#] == bospan[DeleteCases[matrix, Table[0, {nn}]]] &][[ 1]]]]; Tally[
Table[rowrank[B[[i]]], {i, 1, 2^(nn^2)}]][[All,2]], {nn, 0, 4}] // Grid
A355333
Triangle read by rows: T(n,k) is the number of n X n Boolean matrices with Schein rank k, 0 <= k <= n.
Original entry on oeis.org
1, 1, 1, 1, 9, 6, 1, 49, 306, 156, 1, 225, 8550, 40656, 16104, 1, 961, 194850, 5771100, 21165720, 6421800
Offset: 0
Triangle begins:
n\k | 0 1 2 3 4 5
----+--------------------------------------
0 | 1
1 | 1 1
2 | 1 9 6
3 | 1 49 306 156
4 | 1 225 8550 40656 16104
5 | 1 961 194850 5771100 21165720 6421800
Original entry on oeis.org
0, 0, 6, 431, 66056, 27960727, 35744362616, 144901919316449
Offset: 1
a(8) = 0 + 0 + 6 + 425 + 65625 + 27894671 + 35716401889 + 144866174953833.
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