A297735 Number of 3Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2 or 4 neighboring 1s.

1, 3, 17, 34, 92, 223, 700, 1747, 4931, 12767, 35978, 94910, 262007, 698588, 1916541, 5144619, 14035991, 37816996, 102894248, 277866327, 754687018, 2040711739, 5537019209, 14984261865, 40631762944, 110008357730, 298195807995

Offset

1,2

Comments

Row 3 of A297733.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +4*a(n-2) -6*a(n-3) +7*a(n-4) -12*a(n-5) -19*a(n-6) +16*a(n-7) +10*a(n-8) +4*a(n-9)

Example

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

Crossrefs

Cf. A297733.

Sequence in context: A115355 A146021 A146133 * A266062 A031290 A152908

Adjacent sequences: A297732 A297733 A297734 * A297736 A297737 A297738

Keyword

nonn

Author

R. H. Hardin, Jan 04 2018

Status

approved