login
A190419
Number of (n+2)X(n+2) symmetric binary matrices without the pattern 1 1 1 diagonally
1
56, 728, 17472, 768768, 62270208, 9278260992, 2542243511808, 1281290729951232, 1187756506664792064, 2025124843863470469120, 6350791510355843391160320, 36631365431732504680212725760, 388622155865250142152376807587840
OFFSET
1,1
LINKS
EXAMPLE
Some solutions for n=2
..1..0..1..0....1..1..1..0....1..1..0..1....0..1..1..0....1..0..0..1
..0..0..0..0....1..1..0..1....1..0..0..0....1..1..0..0....0..1..0..1
..1..0..0..1....1..0..0..1....0..0..0..1....1..0..0..0....0..0..0..1
..0..0..1..0....0..1..1..0....1..0..1..0....0..0..0..1....1..1..1..1
CROSSREFS
Sequence in context: A240269 A278604 A201098 * A105940 A175602 A227059
KEYWORD
nonn
AUTHOR
R. H. Hardin May 10 2011
STATUS
approved