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A119002 Maximal determinant of real n X n symmetric (0,1) matrices. 4
1, 1, 1, 2, 3, 5, 9, 18, 56, 144 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

The determinant of this 8 X 8 matrix is a(8) = 56:

  {0, 1, 1, 1, 0, 1, 0, 0},

  {1, 0, 1, 1, 0, 1, 0, 0},

  {1, 1, 0, 1, 0, 0, 1, 1},

  {1, 1, 1, 0, 1, 0, 0, 1},

  {0, 0, 0, 1, 1, 1, 0, 1},

  {1, 1, 0, 0, 1, 1, 1, 0},

  {0, 0, 1, 0, 0, 1, 1, 1},

  {0, 0, 1, 1, 1, 0, 1, 0}

and the determinant of this 9 X 9 matrix is a(9) = 144:

  {1, 1, 0, 1, 1, 0, 0, 1, 1},

  {1, 1, 1, 1, 0, 1, 0, 0, 0},

  {0, 1, 1, 1, 0, 0, 1, 1, 1},

  {1, 1, 1, 0, 1, 0, 1, 0, 1},

  {1, 0, 0, 1, 0, 1, 1, 0, 1},

  {0, 1, 0, 0, 1, 1, 1, 1, 0},

  {0, 0, 1, 1, 1, 1, 0, 0, 1},

  {1, 0, 1, 0, 0, 1, 0, 1, 1},

  {1, 0, 1, 1, 1, 0, 1, 1, 0}. - Jean-François Alcover, Nov 18 2017

LINKS

Table of n, a(n) for n=0..9.

Index entries for sequences related to maximal determinants

FORMULA

a(n) <= A003432(n).

CROSSREFS

Cf. A003432, A119003, A119004, A118998.

Sequence in context: A130581 A051236 A003218 * A058770 A049910 A077643

Adjacent sequences:  A118999 A119000 A119001 * A119003 A119004 A119005

KEYWORD

nonn,more

AUTHOR

Giovanni Resta, May 08 2006

EXTENSIONS

a(8) and a(9) from Jean-François Alcover, Nov 18 2017

a(0)=1 prepended by Alois P. Heinz, Nov 18 2017

STATUS

approved

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Last modified January 20 21:36 EST 2019. Contains 319336 sequences. (Running on oeis4.)