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A298282
Number of n X 3 0..1 arrays with every element equal to 0, 1, 2, 3 or 6 king-move adjacent elements, with upper left element zero.
4
4, 25, 70, 205, 614, 1860, 5631, 17034, 51507, 155755, 471038, 1424553, 4308225, 13029159, 39403450, 119165999, 360388207, 1089905354, 3296150132, 9968393611, 30146949453, 91172018210, 275727297765, 833869252932, 2521832029371
OFFSET
1,1
COMMENTS
Column 3 of A298287.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) - a(n-2) + 2*a(n-3) + 4*a(n-4) - a(n-5) + 2*a(n-6) - 2*a(n-7) - 3*a(n-8) - 2*a(n-9) - 2*a(n-10) - 2*a(n-11) for n>12.
Empirical g.f.: x*(4 + 13*x - x^2 + 12*x^3 + 3*x^4 - 13*x^5 - 8*x^6 - 19*x^7 - 13*x^8 - 7*x^9 - 2*x^10 - 4*x^11) / (1 - 3*x + x^2 - 2*x^3 - 4*x^4 + x^5 - 2*x^6 + 2*x^7 + 3*x^8 + 2*x^9 + 2*x^10 + 2*x^11). - Colin Barker, Feb 26 2018
EXAMPLE
Some solutions for n=7:
..0..1..1. .0..1..1. .0..1..1. .0..0..0. .0..1..0. .0..1..0. .0..1..1
..1..0..1. .1..0..0. .1..0..1. .1..1..1. .1..0..1. .0..0..0. .1..0..0
..1..0..1. .1..1..0. .1..0..1. .0..0..0. .1..0..1. .0..1..0. .1..0..1
..1..0..0. .0..1..0. .1..0..1. .0..1..1. .1..1..1. .0..1..0. .1..1..1
..0..1..1. .0..0..0. .1..0..1. .1..0..1. .1..0..1. .1..0..1. .1..0..1
..0..1..0. .0..1..0. .1..0..1. .1..1..0. .0..1..0. .1..1..0. .0..0..1
..0..1..0. .0..1..0. .1..0..0. .0..0..0. .1..0..0. .0..0..0. .1..1..0
CROSSREFS
Cf. A298287.
Sequence in context: A302324 A303017 A281339 * A077205 A180569 A302821
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 16 2018
STATUS
approved