A297334 Number of n X 4 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 0 or 2 neighboring 1s.

8, 53, 334, 2119, 13428, 85065, 538819, 3412881, 21617001, 136920545, 867244348, 5493058792, 34792608560, 220373681804, 1395829787253, 8841077466468, 55998698016470, 354691403972040, 2246587804789311, 14229712668714865

Offset

1,1

Links

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

Formula

Empirical: a(n) = 8*a(n-1) - 10*a(n-2) - 4*a(n-3) + 3*a(n-4) + a(n-5).

Empirical g.f.: x*(1 - x)*(8 - 3*x - 13*x^2 - 4*x^3) / (1 - 8*x + 10*x^2 + 4*x^3 - 3*x^4 - x^5). - Colin Barker, Feb 27 2019

Example

Some solutions for n=5:
..0..0..0..0. .0..0..0..0. .0..0..0..0. .0..1..0..0. .1..0..1..0
..1..0..0..1. .0..0..0..0. .0..1..1..0. .0..0..1..0. .1..0..1..0
..0..0..0..1. .0..0..0..1. .1..1..0..0. .1..0..1..0. .1..0..0..0
..1..0..0..1. .0..0..0..1. .0..0..0..1. .0..0..0..1. .0..0..0..0
..1..0..0..0. .0..0..0..1. .1..0..0..1. .0..1..0..0. .1..0..0..1

Crossrefs

Column 4 of A297338.

Sequence in context: A198846 A291662 A110099 * A091870 A252824 A054418

Adjacent sequences: A297331 A297332 A297333 * A297335 A297336 A297337

Keyword

nonn

Author

R. H. Hardin, Dec 28 2017

Status

approved