A297583 Number of 2 X n 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 or 4 neighboring 1s.

1, 5, 11, 17, 39, 93, 183, 373, 823, 1741, 3599, 7637, 16247, 34125, 71871, 152133, 321127, 676861, 1429135, 3017909, 6367607, 13437869, 28367775, 59874021, 126360711, 266707549, 562939183, 1188130069, 2507681687, 5292853517

Offset

1,2

Links

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

Formula

Empirical: a(n) = a(n-1) + 4*a(n-3) + 2*a(n-4).

Empirical g.f.: x*(1 + 4*x + 6*x^2 + 2*x^3) / (1 - x - 4*x^3 - 2*x^4). - Colin Barker, Mar 01 2019

Example

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

Crossrefs

Row 2 of A297582.

Sequence in context: A277290 A085634 A157478 * A356756 A088903 A094205

Adjacent sequences: A297580 A297581 A297582 * A297584 A297585 A297586

Keyword

nonn

Author

R. H. Hardin, Jan 01 2018

Status

approved