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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..62

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

Adjacent sequences:  A190416 A190417 A190418 * A190420 A190421 A190422

KEYWORD

nonn

AUTHOR

R. H. Hardin May 10 2011

STATUS

approved

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Last modified September 29 22:48 EDT 2022. Contains 357092 sequences. (Running on oeis4.)