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A191574 Number of n X n symmetric binary matrices with each 1 adjacent to no more than 6 knight-move neighboring 1s 0
2, 8, 64, 1024, 31744, 1935544, 233799896, 55948528920, 26536519769600, 24832233133823360, 45900199968106888384, 167513350972291906490904, 1207375485963640678858065184 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..13.

EXAMPLE

Some solutions for n=6

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

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

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

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

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

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

CROSSREFS

Sequence in context: A139680 A153544 A153572 * A191575 A153545 A153573

Adjacent sequences:  A191571 A191572 A191573 * A191575 A191576 A191577

KEYWORD

nonn

AUTHOR

R. H. Hardin Jun 06 2011

STATUS

approved

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Last modified October 3 09:13 EDT 2022. Contains 357231 sequences. (Running on oeis4.)