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A300110
Number of nX3 0..1 arrays with every element equal to 1, 2, 4, 5, 6, 7 or 8 king-move adjacent elements, with upper left element zero.
1
1, 7, 15, 29, 63, 199, 629, 1837, 5397, 15855, 46857, 139131, 411859, 1218209, 3604353, 10667225, 31574175, 93448425, 276561899, 818499247, 2422423269, 7169412933, 21218549729, 62798160031, 185856754621, 550059982899
OFFSET
1,2
COMMENTS
Column 3 of A300115.
LINKS
FORMULA
Empirical: a(n) = 5*a(n-1) -7*a(n-2) +4*a(n-3) -4*a(n-4) +7*a(n-5) -26*a(n-6) +26*a(n-7) +17*a(n-8) -5*a(n-9) -a(n-10) -40*a(n-11) +22*a(n-12) -11*a(n-13) +14*a(n-14) +2*a(n-15) -2*a(n-16) for n>17
EXAMPLE
Some solutions for n=5
..0..1..1. .0..1..1. .0..1..1. .0..0..1. .0..0..1. .0..1..0. .0..0..1
..0..0..1. .0..1..0. .0..1..0. .0..1..1. .0..1..1. .0..0..1. .1..1..0
..0..0..0. .1..1..0. .1..0..1. .1..1..1. .1..1..1. .0..0..0. .1..0..1
..1..0..0. .1..1..0. .0..1..0. .1..1..0. .0..0..1. .1..0..0. .1..1..0
..1..1..0. .1..0..1. .1..1..0. .1..0..0. .0..1..1. .1..1..0. .0..0..1
CROSSREFS
Cf. A300115.
Sequence in context: A298391 A299509 A299309 * A139597 A210675 A293361
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 25 2018
STATUS
approved