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A316752
Number of nX3 0..1 arrays with every element unequal to 1, 2, 4, 6, 7 or 8 king-move adjacent elements, with upper left element zero.
1
1, 9, 15, 17, 79, 185, 315, 970, 2366, 4927, 12747, 31483, 71152, 174182, 426352, 999419, 2406348, 5836950, 13890672, 33315051, 80359905, 192347104, 461162125, 1109224787, 2660354703, 6380696205, 15327646223, 36784405441, 88255373344
OFFSET
1,2
COMMENTS
Column 3 of A316757.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-2) +12*a(n-3) +5*a(n-4) -23*a(n-5) -50*a(n-6) -25*a(n-7) +40*a(n-8) +70*a(n-9) +32*a(n-10) -25*a(n-11) -25*a(n-12) -5*a(n-13) +4*a(n-14) -a(n-15) -2*a(n-16) for n>17
EXAMPLE
Some solutions for n=5
..0..0..1. .0..0..0. .0..1..0. .0..0..0. .0..1..1. .0..0..1. .0..1..0
..0..1..0. .0..1..0. .1..0..0. .0..1..0. .0..0..0. .0..1..0. .0..1..0
..0..0..0. .0..0..0. .1..1..0. .0..0..0. .0..0..0. .0..0..0. .0..0..0
..0..0..1. .1..0..0. .1..0..1. .0..1..0. .0..1..0. .0..1..0. .1..0..0
..0..1..0. .0..1..0. .0..1..1. .0..0..1. .0..0..1. .0..1..0. .0..1..0
CROSSREFS
Cf. A316757.
Sequence in context: A037002 A071149 A289689 * A358725 A358576 A373995
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 12 2018
STATUS
approved