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A070322 Number of primitive n X n real (0,1)-matrices. +0
2
1, 1, 3, 139, 25575, 18077431 (list; graph; listen)
OFFSET

0,3

COMMENT

An n X n nonnegative matrix A is primitive iff every element of A^k is > 0 for some power k. If A is primitive then the power which should have all positive entries is <= n^2 - 2n + 2 (Wielandt).

REFERENCES

Sachkov, V. N. and Tarakanov, V. E., Combinatorics of Nonnegative Matrices. Translations of Mathematical Monographs, 213. American Mathematical Society, Providence, RI, 2002.

Wielandt, H. 1950. Unzerlegbare nicht negativen Matrizen, Math. Z. 52, 642-648.

LINKS

S. J. Leon, Linear Algebra with Applications: THE PERRON-FROBENIUS THEOREM

Index entries for sequences related to binary matrices

FORMULA

For asymptotics see Sachkov and Tarakanov.

MATHEMATICA

Table[ it=Partition[ #, n ]&/@IntegerDigits[ Range[ 0, -1+2^n^2 ], 2, n^2 ]; Count [ it, (q_?MatrixQ) /; (Max@@Table[ Min@@Flatten[ MatrixPower[ q, k ] ], {k, 1, n^2-2n+2} ] )>0 ], {n, 1, 4} ]

CROSSREFS

Sequence in context: A030247 A139956 A016067 this_sequence A053527 A152504 A035331

Adjacent sequences: A070319 A070320 A070321 this_sequence A070323 A070324 A070325

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com), Aug 22 2003

EXTENSIONS

Wouter Meeussen (wouter.meeussen(AT)pandora.be) computed a(0) through a(4), Aug 22, 2003.

Jack Kennedy (kennedy(AT)oldnews.org) computed a(0) through a(5), Aug 22, 2003.

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Last modified December 17 19:39 EST 2009. Contains 170821 sequences.


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