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A298624
Number of nX3 0..1 arrays with every element equal to 2, 3, 4, 5 or 7 king-move adjacent elements, with upper left element zero.
1
0, 3, 8, 26, 138, 611, 2880, 13727, 65070, 310816, 1482870, 7081007, 33819984, 161533363, 771590878, 3685656306, 17605479026, 84097488439, 401715732434, 1918912755293, 9166251659440, 43785309700922, 209153493108094
OFFSET
1,2
COMMENTS
Column 3 of A298629.
LINKS
FORMULA
Empirical: a(n) = 5*a(n-1) +5*a(n-2) -27*a(n-3) -26*a(n-4) +79*a(n-5) +33*a(n-6) -168*a(n-7) +31*a(n-8) +142*a(n-9) -40*a(n-10) -8*a(n-11) for n>12
EXAMPLE
Some solutions for n=5
..0..0..0. .0..0..0. .0..0..0. .0..0..0. .0..1..1. .0..0..0. .0..1..1
..0..0..1. .0..0..0. .0..0..0. .0..0..0. .0..0..1. .0..0..0. .0..0..1
..0..1..1. .1..0..0. .0..0..1. .0..0..1. .1..0..1. .0..1..0. .0..1..1
..1..1..1. .1..1..0. .0..1..1. .0..1..1. .1..1..1. .1..1..0. .1..1..1
..1..1..1. .1..0..0. .0..0..1. .1..1..1. .1..1..1. .1..0..0. .1..1..1
CROSSREFS
Cf. A298629.
Sequence in context: A058802 A054097 A238243 * A088590 A023637 A128894
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 23 2018
STATUS
approved