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

1,1

Links

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

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

Example

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

Crossrefs

Column 3 of A276248.

Sequence in context: A251781 A117642 A220834 * A211618 A362345 A274954

Adjacent sequences: A276240 A276241 A276242 * A276244 A276245 A276246

Keyword

nonn

Author

R. H. Hardin, Aug 25 2016

Status

approved