login
A299523
Number of n X 3 0..1 arrays with every element equal to 1, 3, 4, 5, 6 or 8 king-move adjacent elements, with upper left element zero.
1
0, 4, 1, 12, 35, 60, 269, 873, 1985, 7571, 24138, 65389, 225530, 714174, 2097771, 6892581, 21742964, 66279272, 212788613, 670024373, 2077242857, 6596234246, 20753371856, 64838337595, 204829582459, 644229872136, 2019822965143
OFFSET
1,2
COMMENTS
Column 3 of A299528.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +3*a(n-2) +18*a(n-3) -36*a(n-4) -45*a(n-5) -51*a(n-6) +111*a(n-7) +88*a(n-8) +94*a(n-9) +61*a(n-10) -89*a(n-11) -143*a(n-12) -109*a(n-13) +52*a(n-14) +11*a(n-15) -7*a(n-16) +3*a(n-17) for n>18.
EXAMPLE
Some solutions for n=5
..0..1..0. .0..1..1. .0..0..0. .0..1..0. .0..0..0. .0..1..0. .0..1..0
..0..1..0. .0..1..1. .0..0..0. .0..1..0. .0..0..0. .0..1..0. .0..1..0
..0..0..0. .1..1..1. .0..0..0. .0..0..0. .0..1..1. .1..1..1. .0..0..0
..1..0..1. .0..1..1. .0..1..1. .0..1..0. .0..0..0. .1..0..1. .1..0..0
..1..0..1. .0..1..1. .0..1..1. .0..1..0. .0..0..0. .1..0..1. .1..0..0
CROSSREFS
Cf. A299528.
Sequence in context: A019236 A019237 A019238 * A157404 A135704 A373394
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 11 2018
STATUS
approved