A297221 Number of n X 5 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 1 neighboring 1s.

6, 33, 182, 997, 5570, 30946, 171851, 955316, 5308160, 29497088, 163916530, 910869797, 5061672943, 28127490455, 156303166524, 868569845751, 4826603668246, 26821221189069, 149044329620412, 828232684722634

Offset

1,1

Links

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

Formula

Empirical: a(n) = a(n-1) + 16*a(n-2) + 45*a(n-3) + 39*a(n-4) - 3*a(n-5) - 21*a(n-6) + 8*a(n-7) - 4*a(n-8) + a(n-9).

Empirical g.f.: x*(6 + 27*x + 53*x^2 + 17*x^3 - 58*x^4 - 35*x^5 + 47*x^6 - 13*x^7 + x^8) / ((1 + 2*x + x^2 - x^3)*(1 - 3*x - 11*x^2 - 19*x^3 + 7*x^4 - 3*x^5 + x^6)). - Colin Barker, Feb 26 2019

Example

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

Crossrefs

Column 5 of A297224.

Sequence in context: A050151 A009162 A012718 * A006630 A367850 A180035

Adjacent sequences: A297218 A297219 A297220 * A297222 A297223 A297224

Keyword

nonn

Author

R. H. Hardin, Dec 27 2017

Status

approved