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A202414
Number of (n+2) X 3 binary arrays with no more than one of any consecutive three bits set in any row or column.
1
34, 94, 265, 739, 2059, 5746, 16033, 44728, 124786, 348145, 971293, 2709817, 7560148, 21092137, 58845166, 164172730, 458027185, 1277854735, 3565100011, 9946309042, 27749309485, 77418082780, 215989502182, 602591324641
OFFSET
1,1
COMMENTS
Column 1 of A202421.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +a(n-2) +3*a(n-3) +a(n-4).
Empirical g.f.: x*(34 + 26*x + 43*x^2 + 13*x^3) / (1 - 2*x - x^2 - 3*x^3 - x^4). - Colin Barker, May 28 2018
EXAMPLE
Some solutions for n=5:
..0..1..0....0..0..0....1..0..0....0..0..1....0..0..0....0..0..1....0..0..1
..1..0..0....0..0..1....0..1..0....1..0..0....0..0..1....0..0..0....0..0..0
..0..0..0....1..0..0....0..0..0....0..0..0....0..1..0....1..0..0....1..0..0
..0..0..1....0..0..0....1..0..0....0..0..1....0..0..0....0..0..0....0..0..0
..0..1..0....0..1..0....0..0..0....0..0..0....0..0..0....0..0..1....0..0..0
..0..0..0....0..0..0....0..0..1....0..0..0....0..1..0....1..0..0....0..1..0
..1..0..0....0..0..0....1..0..0....0..0..0....0..0..0....0..0..0....1..0..0
CROSSREFS
Cf. A202421.
Sequence in context: A260467 A202421 A365248 * A160062 A247218 A233031
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 19 2011
STATUS
approved