A276243 - OEIS

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

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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