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A187309 Half the number of (n+2)X3 binary arrays with each 3X3 subblock having sum 3, 4, 5 or 6 1
210, 1472, 10262, 71836, 502545, 3516295, 24602854, 172142801, 1204456419, 8427400133, 58965241283, 412570864570, 2886695849049, 20197773668299, 141320763334969, 988799977661816, 6918483687265734, 48407582536978550 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A187317

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n)=7*a(n-1)+a(n-2)-6*a(n-3)-6*a(n-4)-27*a(n-5)+90*a(n-6)-81*a(n-8)

EXAMPLE

Some solutions for 4X3 with a(1,1)=0

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

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

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

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

CROSSREFS

Sequence in context: A118281 A047633 A187317 * A104902 A135201 A187663

Adjacent sequences:  A187306 A187307 A187308 * A187310 A187311 A187312

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 08 2011

STATUS

approved

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Last modified November 23 19:03 EST 2017. Contains 295128 sequences.