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A299309
Number of nX3 0..1 arrays with every element equal to 1, 2, 4, 5, 6 or 7 king-move adjacent elements, with upper left element zero.
1
1, 7, 15, 29, 63, 199, 593, 1657, 4689, 13395, 38357, 109855, 313667, 896417, 2563517, 7330205, 20956899, 59914557, 171302635, 489779503, 1400327457, 4003663145, 11446878297, 32727841823, 93572301793, 267532776375, 764903730599
OFFSET
1,2
COMMENTS
Column 3 of A299314.
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) -3*a(n-2) +a(n-3) -3*a(n-4) -6*a(n-5) -8*a(n-6) +18*a(n-7) +27*a(n-8) -18*a(n-9) +15*a(n-10) -55*a(n-11) +21*a(n-12) -6*a(n-13) +14*a(n-14) +2*a(n-15) -2*a(n-16) for n>17
EXAMPLE
Some solutions for n=6
..0..1..1. .0..1..0. .0..1..0. .0..1..0. .0..1..0. .0..1..1. .0..1..1
..0..0..1. .1..0..0. .1..0..1. .0..1..0. .0..0..1. .0..0..1. .0..0..1
..0..0..0. .0..0..0. .0..0..0. .1..1..1. .0..0..0. .0..0..0. .0..0..0
..0..0..0. .0..0..0. .0..0..0. .1..1..1. .0..0..0. .0..0..0. .0..0..0
..1..0..1. .1..0..1. .0..0..1. .1..1..0. .1..0..0. .1..0..0. .0..0..1
..1..0..1. .0..1..0. .0..1..0. .1..0..0. .0..1..0. .0..1..0. .0..1..1
CROSSREFS
Cf. A299314.
Sequence in context: A198589 A298391 A299509 * A300110 A139597 A210675
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 06 2018
STATUS
approved