A276301 Number of 4 X n 0..2 arrays with no element equal to any value at offset (-2,-1) (-1,1) or (0,-1) and new values introduced in order 0..2.

14, 31, 189, 1017, 5909, 33461, 191289, 1089941, 6217661, 35454545, 202199549, 1153097557, 6575970385, 37501690413, 213866533133, 1219647879417, 6955465873669, 39665957261253, 226208890949593, 1290034710761669

Offset

1,1

Links

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

Formula

Empirical: a(n) = 4*a(n-1) + 10*a(n-2) - 6*a(n-4) - 22*a(n-5) + 15*a(n-6) for n>8.

Empirical g.f.: x*(14 - 25*x - 75*x^2 - 49*x^3 + 35*x^4 + 149*x^5 - 39*x^6 - 30*x^7) / ((1 - x)*(1 - 3*x - 13*x^2 - 13*x^3 - 7*x^4 + 15*x^5)). - Colin Barker, Feb 05 2019

Example

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

Crossrefs

Row 4 of A276299.

Sequence in context: A156203 A338389 A196135 * A101183 A101444 A222414

Adjacent sequences: A276298 A276299 A276300 * A276302 A276303 A276304

Keyword

nonn

Author

R. H. Hardin, Aug 28 2016

Status

approved