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A275403 Number of 4_X_n 0..2 arrays with no element equal to any value at offset (-2,-1) (-2,0) or (-1,1) and new values introduced in order 0..2. 1
6, 31, 178, 1011, 5758, 32771, 186538, 1061795, 6043830, 34402035, 195819682, 1114623859, 6344543534, 36113737251, 205562777626, 1170082606339, 6660219918630, 37910596295955, 215790669012498, 1228300722808403 (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) + 11*a(n-2) + 25*a(n-3) + 2*a(n-4) - 24*a(n-5) for n>6.

Empirical g.f.: x*(6 + 13*x + 19*x^2 - 14*x^3 - 20*x^4 + 8*x^5) / (1 - 3*x - 11*x^2 - 25*x^3 - 2*x^4 + 24*x^5). - Colin Barker, Feb 04 2019

EXAMPLE

Some solutions for n=4:

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

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

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

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

CROSSREFS

Row 4 of A275401.

Sequence in context: A343350 A036729 A321799 * A338674 A199320 A097176

Adjacent sequences:  A275400 A275401 A275402 * A275404 A275405 A275406

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jul 26 2016

STATUS

approved

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Last modified July 30 04:49 EDT 2021. Contains 346348 sequences. (Running on oeis4.)