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A303685 Number of nX3 0..1 arrays with every element unequal to 2, 3 or 4 king-move adjacent elements, with upper left element zero. 1
0, 5, 2, 20, 27, 108, 191, 599, 1261, 3503, 8019, 20956, 49932, 126833, 308197, 772321, 1894368, 4716189, 11620491, 28839210, 71214717, 176468284, 436228102, 1080165740, 2671530008, 6612751510, 16359100711, 40486188269, 100169626090 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 3 of A303690.

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) +6*a(n-2) -3*a(n-3) -9*a(n-4) +7*a(n-5) +3*a(n-6) -20*a(n-7) -3*a(n-8) +12*a(n-9) -12*a(n-11) -3*a(n-12) +2*a(n-13) -5*a(n-14) +a(n-15) +2*a(n-16) for n>18

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A303690.

Sequence in context: A304635 A306198 A276533 * A189746 A191667 A130329

Adjacent sequences:  A303682 A303683 A303684 * A303686 A303687 A303688

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 28 2018

STATUS

approved

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Last modified October 19 03:54 EDT 2019. Contains 328211 sequences. (Running on oeis4.)