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.

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

R. H. Hardin, Table of n, a(n) for n = 1..210

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

Adjacent sequences: A202411 A202412 A202413 * A202415 A202416 A202417

Keyword

nonn

Author

R. H. Hardin, Dec 19 2011

Status

approved