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A192258
Number of n X n symmetric binary matrices with each element either the sum mod 2 of its horizontal neighbors or the sum mod 2 of its vertical neighbors
1
1, 2, 3, 10, 52, 305, 3336, 53160, 1210187, 43234473, 2296063392, 180971357507, 21523051916415, 3822241812458992, 1013512678870403979, 402404564958432626790, 238779216876700299752228
OFFSET
1,2
LINKS
EXAMPLE
Some solutions for 5X5
..1..1..0..1..1....1..1..0..0..0....1..1..0..1..1....0..0..0..1..0
..1..1..0..0..0....1..1..0..1..0....1..0..1..1..0....0..0..0..1..0
..0..0..0..0..0....0..0..1..1..0....0..1..1..0..1....0..0..0..0..0
..1..0..0..0..0....0..1..1..1..0....1..1..0..1..1....1..1..0..0..0
..1..0..0..0..0....0..0..0..0..0....1..0..1..1..1....0..0..0..0..0
CROSSREFS
Sequence in context: A020098 A013081 A054921 * A052561 A181927 A066526
KEYWORD
nonn
AUTHOR
R. H. Hardin Jun 26 2011
STATUS
approved