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A005020
The number of n X n (0,1)-matrices with a 1-width of 2.
(Formerly M2182)
2
0, 2, 168, 32738, 20825760, 47942081642
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OFFSET
1,2
COMMENTS
Determining the 1-width of a matrix is NP-complete. -
Sean A. Irvine
, Mar 06 2020
REFERENCES
Lam, Clement W. H. The distribution of 1-widths of (0, 1)-matrices. Discrete Math. 20 (1977/78), no. 2, 109-122.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Table of n, a(n) for n=1..6.
Sean A. Irvine,
Java program
(github)
Index entries for sequences related to binary matrices
CROSSREFS
Sequence in context:
A297407
A142602
A200042
*
A157316
A007760
A230511
Adjacent sequences:
A005017
A005018
A005019
*
A005021
A005022
A005023
KEYWORD
nonn
AUTHOR
N. J. A. Sloane
EXTENSIONS
a(1) corrected and title improved by
Sean A. Irvine
, Mar 06 2020
STATUS
approved
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Last modified March 19 04:26 EDT 2024. Contains 370952 sequences. (Running on oeis4.)