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A190421 Number of (n+2)X(n+2) symmetric binary matrices without the pattern 1 1 1 diagonally, vertically or horizontally 1
41, 418, 7196, 204512, 10058896, 841847949, 119691599225, 29020894570697, 11983601899221278, 8426537547806386479, 10092907365256801760968, 20589467353675961113678823, 71537585310236891049512559411 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..14

EXAMPLE

Some solutions for n=2

..1..0..1..0....1..1..0..1....1..0..0..1....0..0..1..1....1..0..1..0

..0..1..0..1....1..0..0..1....0..1..0..1....0..0..0..1....0..1..1..0

..1..0..0..0....0..0..1..0....0..0..0..0....1..0..1..0....1..1..0..0

..0..1..0..0....1..1..0..1....1..1..0..0....1..1..0..0....0..0..0..0

CROSSREFS

Sequence in context: A069594 A124338 A008356 * A178387 A068849 A145293

Adjacent sequences:  A190418 A190419 A190420 * A190422 A190423 A190424

KEYWORD

nonn

AUTHOR

R. H. Hardin May 10 2011

STATUS

approved

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Last modified October 5 06:51 EDT 2022. Contains 357252 sequences. (Running on oeis4.)