A275187 Number of 7 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.

32, 65, 389, 2386, 14643, 90793, 561044, 3472521, 21488129, 132962186, 822814111, 5091567885, 31507279460, 194970115869, 1206493799669, 7465907869266, 46199772632427, 285888830879985, 1769108624416628, 10947420840825089

Offset

1,1

Links

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

Formula

Empirical: a(n) = 2*a(n-1) + 20*a(n-2) + 43*a(n-3) - 20*a(n-4) - 92*a(n-5) - 176*a(n-6) - 16*a(n-7) - 16*a(n-8) + 64*a(n-9) for n>10.

Empirical g.f.: x*(32 + x - 381*x^2 - 1068*x^3 - 64*x^4 + 1304*x^5 + 3392*x^6 + 384*x^7 + 496*x^8 - 1216*x^9) / (1 - 2*x - 20*x^2 - 43*x^3 + 20*x^4 + 92*x^5 + 176*x^6 + 16*x^7 + 16*x^8 - 64*x^9). - Colin Barker, Feb 01 2019

Example

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

Crossrefs

Row 7 of A275183.

Sequence in context: A339358 A249116 A110562 * A045048 A132773 A116349

Adjacent sequences: A275184 A275185 A275186 * A275188 A275189 A275190

Keyword

nonn

Author

R. H. Hardin, Jul 19 2016

Status

approved