login
A296822
Number of nX3 0..1 arrays with each 1 adjacent to 2, 3 or 4 king-move neighboring 1s.
1
1, 21, 94, 352, 2133, 11930, 60772, 326592, 1772900, 9465417, 50680823, 272327824, 1460652327, 7831666171, 42016275835, 225392908023, 1208952350028, 6484936659738, 34786259866407, 186595358346906, 1000910649083880
OFFSET
1,2
COMMENTS
Column 3 of A296827.
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) +3*a(n-2) +35*a(n-3) -38*a(n-4) -111*a(n-5) -176*a(n-6) +144*a(n-7) +267*a(n-8) +147*a(n-9) -110*a(n-10) -107*a(n-11) +56*a(n-12) +58*a(n-13) +49*a(n-14) -10*a(n-15) -18*a(n-16)
EXAMPLE
Some solutions for n=7
..0..0..0. .0..1..0. .0..0..1. .1..0..0. .1..1..0. .1..0..0. .0..1..0
..0..0..1. .0..1..1. .1..1..1. .1..1..0. .1..0..0. .1..1..0. .1..1..0
..0..1..1. .0..0..0. .0..1..0. .1..0..1. .0..1..1. .0..1..0. .1..0..1
..0..0..0. .0..1..0. .0..0..0. .0..1..1. .0..1..1. .0..1..1. .0..1..0
..1..1..0. .0..1..1. .0..0..1. .0..1..0. .0..0..0. .0..1..0. .0..1..1
..1..0..1. .1..1..0. .0..1..1. .1..0..0. .0..1..0. .1..0..1. .1..0..1
..1..1..1. .0..0..0. .0..0..0. .1..1..0. .1..1..0. .0..1..0. .0..1..0
CROSSREFS
Cf. A296827.
Sequence in context: A218844 A219423 A123213 * A174084 A193218 A220157
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 21 2017
STATUS
approved