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A305680 Number of nX3 0..1 arrays with every element unequal to 0, 2, 3, 4, 5 or 6 king-move adjacent elements, with upper left element zero. 2
1, 8, 25, 139, 818, 4869, 29339, 177688, 1078090, 6547420, 39780381, 241739361, 1469140840, 8928868485, 54267151921, 329823144348, 2004595773274, 12183532071766, 74049126308943, 450056268717553, 2735355386324434 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 3 of A305685.

LINKS

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

FORMULA

Empirical: a(n) = 7*a(n-1) -3*a(n-2) -6*a(n-3) -61*a(n-4) -4*a(n-5) +53*a(n-6) +92*a(n-7) +78*a(n-8) -9*a(n-9) -8*a(n-10) -2*a(n-11) +8*a(n-12) +10*a(n-13) +2*a(n-14) for n>16

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A305685.

Sequence in context: A275151 A302617 A042189 * A316927 A004246 A220535

Adjacent sequences:  A305677 A305678 A305679 * A305681 A305682 A305683

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jun 08 2018

STATUS

approved

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Last modified July 1 06:55 EDT 2022. Contains 354952 sequences. (Running on oeis4.)