A297728 Number of nX3 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2 or 4 neighboring 1s.

1, 8, 17, 39, 151, 385, 1026, 3272, 8945, 24901, 74075, 208094, 588488, 1706080, 4842007, 13774525, 39552499, 112678747, 321268652, 919208426, 2622325086, 7483126614, 21382095851, 61030208100, 174213589553, 497546313443

Offset

1,2

Comments

Column 3 of A297733.

Links

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

Formula

Empirical: a(n) = a(n-1) +a(n-2) +13*a(n-3) -2*a(n-4) +4*a(n-5) -11*a(n-6) -3*a(n-7) -a(n-8)

Example

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

Crossrefs

Cf. A297733.

Sequence in context: A209376 A159696 A049713 * A188129 A041849 A041124

Adjacent sequences: A297725 A297726 A297727 * A297729 A297730 A297731

Keyword

nonn

Author

R. H. Hardin, Jan 04 2018

Status

approved