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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 (list; graph; refs; listen; history; text; internal format)
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
Sean A. Irvine, Java program (github)
CROSSREFS
Sequence in context: A297407 A142602 A200042 * A157316 A007760 A230511
KEYWORD
nonn
AUTHOR
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.)