A275185 Number of 5 X n 0..2 arrays with no element equal to any value at offset (-2,-1) (-1,0) or (-1,1) and new values introduced in order 0..2.

8, 21, 85, 353, 1465, 6081, 25241, 104769, 434873, 1805057, 7492377, 31099137, 129085369, 535803713, 2223998105, 9231305153, 38317026745, 159045174401, 660159977241, 2740172389249, 11373826014393, 47210138571457

Offset

1,1

Links

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

Formula

Empirical: a(n) = 2*a(n-1) + 7*a(n-2) + 8*a(n-3) for n>5.

Empirical g.f.: x*(8 + 5*x - 13*x^2 - 28*x^3 - 4*x^4) / (1 - 2*x - 7*x^2 - 8*x^3). - Colin Barker, Feb 01 2019

Example

Some solutions for n=4:
..0..0..0..1. .0..0..0..1. .0..1..1..1. .0..1..1..1. .0..0..0..1
..2..2..2..2. .1..2..2..0. .2..0..0..0. .2..2..0..0. .1..2..2..0
..1..1..1..1. .0..1..1..2. .1..1..2..2. .1..1..2..2. .0..1..1..2
..0..0..0..0. .2..2..0..0. .0..0..1..1. .0..0..0..1. .2..0..0..0
..2..2..2..2. .0..1..2..2. .1..2..2..0. .2..2..2..0. .1..2..2..2

Crossrefs

Row 5 of A275183.

Sequence in context: A232049 A225658 A226313 * A264238 A188700 A054855

Adjacent sequences: A275182 A275183 A275184 * A275186 A275187 A275188

Keyword

nonn

Author

R. H. Hardin, Jul 19 2016

Status

approved