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A305644 Number of nX3 0..1 arrays with every element unequal to 0, 1, 3, 4, 5 or 6 king-move adjacent elements, with upper left element zero. 1
3, 9, 13, 31, 79, 168, 430, 1241, 3577, 10976, 35220, 115104, 382846, 1287463, 4355297, 14794917, 50378019, 171779607, 586281739, 2002004862, 6838403076, 23363178277, 79828543393, 272780054792, 932149927652, 3185441895514 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A305649.

LINKS

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

FORMULA

Empirical: a(n) = 5*a(n-1) -7*a(n-2) +17*a(n-3) -52*a(n-4) +50*a(n-5) -48*a(n-6) +92*a(n-7) -45*a(n-8) -17*a(n-9) +68*a(n-10) -44*a(n-11) -5*a(n-12) -127*a(n-13) +174*a(n-14) -54*a(n-15) -16*a(n-16) +8*a(n-17) for n>19

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A305649.

Sequence in context: A215443 A304664 A068885 * A316920 A018292 A089147

Adjacent sequences:  A305641 A305642 A305643 * A305645 A305646 A305647

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jun 07 2018

STATUS

approved

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Last modified January 23 10:36 EST 2020. Contains 331171 sequences. (Running on oeis4.)