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A213545 Number of n X n binary matrices with zero diagonal and directed 3-loops in at most one direction (3-loop: x(i,j)*x(j,k)*x(k,i)=1, and i,j,k all different) 0
1, 4, 63, 3861, 912060, 823931109, 2827364948343, 36639801307739070, 1783839514317792934491 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
EXAMPLE
Some solutions for n=4
..0..0..1..1....0..0..0..1....0..1..0..1....0..1..1..1....0..0..1..0
..1..0..1..0....1..0..0..0....1..0..1..1....1..0..0..1....0..0..0..0
..0..1..0..0....0..1..0..0....1..0..0..1....1..1..0..0....0..1..0..1
..1..0..0..0....1..1..1..0....0..1..0..0....1..0..1..0....0..1..0..0
CROSSREFS
Sequence in context: A351779 A203512 A354653 * A362386 A361683 A111444
KEYWORD
nonn
AUTHOR
R. H. Hardin Jun 14 2012
STATUS
approved

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Last modified June 21 14:19 EDT 2024. Contains 373547 sequences. (Running on oeis4.)