A276243 Number of n X 3 0..2 arrays with no element equal to any value at offset (-2,-1) (-1,1) or (0,-2) and new values introduced in order 0..2.

3, 24, 85, 347, 1404, 5671, 23000, 93204, 377421, 1529844, 6199862, 25119735, 101801648, 412550060, 1671737809, 6774642628, 27453734102, 111251981923, 450838255264, 1826978135284, 7403609436805, 30002352111444, 121581392056470

Offset: 1

Author

R. H. Hardin, Aug 25 2016

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Column 3 of A276248.

Formula

Empirical: a(n) = 5*a(n-1) - 4*a(n-2) + 17*a(n-3) - 83*a(n-4) + 54*a(n-5) + 56*a(n-6) for n>9.

Empirical g.f.: x*(3 + 9*x - 23*x^2 - 33*x^3 - 150*x^4 + 424*x^5 - 47*x^6 - 113*x^7 + 28*x^8) / ((1 - 2*x)*(1 - 3*x - 2*x^2 - 21*x^3 + 41*x^4 + 28*x^5)). - Colin Barker, Feb 05 2019