A275144 Number of 4 X n 0..2 arrays with no element equal to any value at offset (-2,-2) (-1,-2) or (0,-1) and new values introduced in order 0..2.

14, 216, 400, 1088, 2320, 6464, 17872, 49792, 139664, 392448, 1102416, 3095808, 8693584, 24414784, 68567696, 192568832, 540817040, 1518847552, 4265581328, 11979603776, 33643929040, 94486756224, 265359817104, 745245528576

Offset

1,1

Links

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

Formula

Empirical: a(n) = 5*a(n-1) - 9*a(n-2) + 10*a(n-3) - 6*a(n-4) + a(n-5) for n>9.

Empirical g.f.: 2*x*(7 + 73*x - 277*x^2 + 446*x^3 - 798*x^4 + 969*x^5 - 1132*x^6 + 768*x^7 - 128*x^8) / ((1 - x)*(1 - 4*x + 5*x^2 - 5*x^3 + x^4)). - Colin Barker, Feb 01 2019

Example

Some solutions for n=5:
..0..1..0..1..2. .0..1..0..2..1. .0..1..0..1..2. .0..1..0..2..1
..0..2..1..0..1. .1..2..1..0..1. .1..2..1..0..1. .0..2..1..2..1
..1..0..1..0..2. .1..0..2..0..2. .2..0..2..0..2. .0..2..1..0..2
..2..0..2..1..2. .1..2..0..1..0. .0..1..0..1..0. .2..0..2..0..2

Crossrefs

Row 4 of A275142.

Sequence in context: A331494 A208430 A275224 * A275354 A121972 A240781

Adjacent sequences: A275141 A275142 A275143 * A275145 A275146 A275147

Keyword

nonn

Author

R. H. Hardin, Jul 17 2016

Status

approved