A275179 Number of n X 4 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.

14, 64, 89, 141, 353, 914, 2386, 6228, 16249, 42451, 111108, 291065, 762378, 1995896, 5223852, 13673069, 35794346, 93714905, 245360591, 642367172, 1681704625, 4402670689, 11526266952, 30176270194, 79002891883, 206832552922

Offset

1,1

Links

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

Formula

Empirical: a(n) = 8*a(n-1) - 28*a(n-2) + 57*a(n-3) - 70*a(n-4) + 47*a(n-5) - 12*a(n-6) - a(n-7) - 2*a(n-8) + a(n-9) for n>12.

Empirical g.f.: x*(14 - 48*x - 31*x^2 + 423*x^3 - 951*x^4 + 787*x^5 + 311*x^6 - 920*x^7 + 378*x^8 + 125*x^9 + 29*x^10 - 32*x^11) / ((1 - 3*x + x^2)*(1 - 5*x + 12*x^2 - 16*x^3 + 10*x^4 - x^5 - x^6 - x^7)). - Colin Barker, Feb 01 2019

Example

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

Crossrefs

Column 4 of A275183.

Sequence in context: A229738 A239856 A214483 * A050396 A344597 A069964

Adjacent sequences: A275176 A275177 A275178 * A275180 A275181 A275182

Keyword

nonn

Author

R. H. Hardin, Jul 19 2016

Status

approved