A275186 Number of 6 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.

16, 37, 181, 914, 4603, 23313, 117916, 596625, 3018913, 15274618, 77286999, 391054261, 1978648444, 10011529573, 50656125413, 256308871218, 1296866472387, 6561859014441, 33201563019036, 167992603723721, 850005614599481

Offset

1,1

Links

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

Formula

Empirical: a(n) = 2*a(n-1) + 12*a(n-2) + 19*a(n-3) - 4*a(n-4) - 12*a(n-5) - 16*a(n-6) for n>7.

Empirical g.f.: x*(16 + 5*x - 85*x^2 - 196*x^3 - 36*x^4 + 40*x^5 + 112*x^6) / ((1 - x)*(1 - x - 13*x^2 - 32*x^3 - 28*x^4 - 16*x^5)). - Colin Barker, Feb 01 2019

Example

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

Crossrefs

Row 6 of A275183.

Sequence in context: A070587 A350288 A354473 * A224745 A070586 A166112

Adjacent sequences: A275183 A275184 A275185 * A275187 A275188 A275189

Keyword

nonn

Author

R. H. Hardin, Jul 19 2016

Status

approved