A297988 Number of nX3 0..1 arrays with every element equal to 1, 2, 3 or 6 king-move adjacent elements, with upper left element zero.

1, 17, 48, 146, 424, 1274, 3820, 11529, 34783, 104826, 315711, 950990, 2864947, 8631274, 26003209, 78338270, 236004118, 710993764, 2141965614, 6452965003, 19440438745, 58566971613, 176440981687, 531552505076, 1601374384608

Offset

1,2

Comments

Column 3 of A297993.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) -a(n-2) +a(n-3) +6*a(n-4) +4*a(n-6) -2*a(n-8) -a(n-9) -2*a(n-10) -2*a(n-11) for n>13

Example

Some solutions for n=7
..0..0..0. .0..1..1. .0..0..0. .0..1..1. .0..1..1. .0..0..0. .0..1..0
..0..1..1. .1..0..1. .1..1..0. .1..0..0. .1..0..1. .1..1..1. .1..0..1
..1..0..1. .1..0..1. .1..0..1. .1..0..1. .1..0..0. .0..0..0. .1..0..1
..0..1..0. .0..0..1. .1..0..1. .1..1..1. .0..1..1. .1..1..0. .0..1..0
..1..0..0. .1..1..0. .0..0..1. .1..0..1. .0..0..1. .1..0..1. .0..1..0
..1..1..1. .0..1..0. .1..1..0. .0..0..1. .1..1..0. .0..1..0. .0..1..0
..0..0..0. .0..0..1. .0..0..0. .1..1..1. .0..0..0. .0..1..0. .1..1..0

Crossrefs

Cf. A297993.

Sequence in context: A031122 A051869 A297818 * A210372 A239130 A181426

Adjacent sequences: A297985 A297986 A297987 * A297989 A297990 A297991

Keyword

nonn

Author

R. H. Hardin, Jan 10 2018

Status

approved