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A275126 Number of n X 3 0..2 arrays with no element equal to any value at offset (-2,-2) (-1,0) or (-1,1) and new values introduced in order 0..2. 1
5, 16, 45, 129, 373, 1083, 3148, 9157, 26623, 77372, 224857, 653525, 1899462, 5520787, 16046124, 46637722, 135551305, 393976458, 1145083415, 3328158969, 9673218248, 28114986916, 81715561920, 237504397813, 690301064559 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) - 2*a(n-2) + 4*a(n-3) + a(n-4) + 3*a(n-5) + 8*a(n-6) + a(n-7) - 3*a(n-8) - a(n-9) for n>10.

Empirical g.f.: x*(5 + x + 7*x^2 + 6*x^3 + 7*x^4 + 11*x^5 - 4*x^6 - 10*x^7 - 5*x^8 - x^9) / (1 - 3*x + 2*x^2 - 4*x^3 - x^4 - 3*x^5 - 8*x^6 - x^7 + 3*x^8 + x^9). - Colin Barker, Jan 31 2019

EXAMPLE

Some solutions for n=4:

..0..1..2. .0..0..0. .0..0..0. .0..1..0. .0..0..0. .0..0..1. .0..1..1

..2..0..1. .1..1..2. .1..1..1. .2..2..2. .1..1..1. .2..2..0. .2..2..0

..1..2..2. .2..0..1. .2..2..2. .0..1..1. .2..0..2. .0..1..1. .1..1..1

..0..1..0. .1..2..0. .1..1..0. .2..0..0. .1..1..0. .2..0..0. .0..2..0

CROSSREFS

Column 3 of A275131.

Sequence in context: A189390 A099327 A004146 * A071101 A110580 A055552

Adjacent sequences:  A275123 A275124 A275125 * A275127 A275128 A275129

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jul 17 2016

STATUS

approved

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Last modified March 30 16:16 EDT 2020. Contains 333127 sequences. (Running on oeis4.)