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A317858 Number of nX3 0..1 arrays with every element unequal to 1, 2 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 1
1, 6, 4, 19, 32, 72, 164, 331, 790, 1700, 3879, 8689, 19763, 44787, 101708, 232136, 528496, 1206975, 2755982, 6298876, 14399412, 32932776, 75341117, 172383450, 394513860, 902958422, 2066919648, 4731632878, 10832452949, 24800620478 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 3 of A317863.

LINKS

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

FORMULA

Empirical: a(n) = 5*a(n-2) +8*a(n-3) -2*a(n-4) -26*a(n-5) -32*a(n-6) +6*a(n-7) +40*a(n-8) +32*a(n-9) -3*a(n-10) -16*a(n-11) +17*a(n-12) +6*a(n-13) -20*a(n-14) -6*a(n-15) +19*a(n-16) +14*a(n-17) -14*a(n-19) -5*a(n-20) +2*a(n-21) -10*a(n-22) +3*a(n-24) +a(n-26) for n>32

EXAMPLE

Some solutions for n=5

..0..1..0. .0..1..1. .0..1..0. .0..0..0. .0..1..1. .0..1..0. .0..1..0

..0..0..1. .0..1..0. .0..0..0. .1..1..0. .1..1..0. .1..1..0. .1..1..0

..1..1..1. .0..0..0. .1..0..1. .1..0..1. .1..1..1. .0..0..0. .1..1..0

..1..0..0. .1..0..1. .0..0..0. .0..1..1. .0..1..1. .0..1..1. .0..0..0

..0..1..0. .0..0..0. .0..1..0. .0..0..0. .1..0..1. .1..0..1. .0..1..0

CROSSREFS

Cf. A317863.

Sequence in context: A180495 A213761 A160248 * A212891 A107983 A009278

Adjacent sequences:  A317855 A317856 A317857 * A317859 A317860 A317861

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 09 2018

STATUS

approved

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Last modified May 17 22:15 EDT 2021. Contains 343992 sequences. (Running on oeis4.)