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A304546
Number of nX3 0..1 arrays with every element unequal to 0, 2, 3, 4 or 6 king-move adjacent elements, with upper left element zero.
2
1, 8, 13, 60, 217, 749, 2822, 10516, 38934, 145185, 542474, 2025645, 7568821, 28294956, 105785530, 395536988, 1479072597, 5531090102, 20684425965, 77354433339, 289289280136, 1081888995062, 4046087436916, 15131752735177
OFFSET
1,2
COMMENTS
Column 3 of A304551.
LINKS
FORMULA
Empirical: a(n) = 5*a(n-1) -3*a(n-2) -a(n-3) -18*a(n-4) -24*a(n-5) +44*a(n-6) +42*a(n-7) +52*a(n-8) +31*a(n-9) -132*a(n-10) -80*a(n-11) +48*a(n-12) -31*a(n-13) +13*a(n-14) +17*a(n-15) -82*a(n-16) -39*a(n-17) -2*a(n-19) -a(n-20) for n>21
EXAMPLE
Some solutions for n=5
..0..1..0. .0..0..1. .0..1..1. .0..1..1. .0..1..1. .0..0..0. .0..1..1
..1..1..0. .1..1..0. .1..0..0. .0..1..1. .1..0..0. .0..0..0. .0..1..1
..1..0..1. .0..0..0. .0..1..0. .1..1..1. .1..1..1. .1..1..1. .1..0..0
..0..0..0. .0..1..1. .0..0..1. .1..0..0. .1..0..0. .0..0..0. .1..0..0
..1..0..1. .1..0..0. .1..0..1. .0..1..1. .0..1..1. .0..0..0. .0..1..1
CROSSREFS
Cf. A304551.
Sequence in context: A359553 A081966 A316527 * A377561 A166670 A107764
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 14 2018
STATUS
approved