A202771 Number of (n+2) X 4 binary arrays avoiding patterns 000 and 011 in rows, columns and nw-to-se diagonals.

201, 550, 1239, 2600, 5330, 10322, 19712, 36877, 67818, 123780, 223588, 401471, 717459, 1276509, 2265021, 4008850, 7081983, 12493424, 22013308, 38753966, 68177210, 119873325, 210680744, 370151150, 650162408, 1141764563, 2004758257

Offset

1,1

Comments

Column 2 of A202777.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) -2*a(n-3) -11*a(n-4) +9*a(n-5) +10*a(n-6) +11*a(n-7) -23*a(n-8) -8*a(n-9) -3*a(n-10) +20*a(n-11) +3*a(n-13) -8*a(n-14) -4*a(n-16) +3*a(n-17) +a(n-18) +a(n-19) -a(n-20).

Example

Some solutions for n=3
..1..1..1..1....1..1..0..0....1..1..0..1....1..1..0..1....1..1..1..0
..1..1..1..1....1..1..0..1....0..1..0..1....1..1..1..0....0..1..0..1
..1..1..1..1....1..1..1..0....1..1..1..1....1..1..0..0....1..1..1..0
..0..1..0..1....1..1..0..0....0..1..0..1....0..1..0..1....0..1..0..0
..1..1..1..1....0..1..0..1....1..1..0..1....0..0..1..0....0..1..0..1

Crossrefs

Cf. A202777.

Sequence in context: A259768 A076192 A157956 * A183350 A226566 A061697

Adjacent sequences: A202768 A202769 A202770 * A202772 A202773 A202774

Keyword

nonn

Author

R. H. Hardin, Dec 23 2011

Status

approved