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A304225
Number of nX3 0..1 arrays with every element unequal to 0, 1, 2 or 7 king-move adjacent elements, with upper left element zero.
1
4, 3, 5, 6, 11, 16, 22, 33, 49, 71, 104, 153, 224, 328, 481, 705, 1033, 1514, 2219, 3252, 4766, 6985, 10237, 15003, 21988, 32225, 47228, 69216, 101441, 148669, 217885, 319326, 467995, 685880, 1005206, 1473201, 2159081, 3164287, 4637488, 6796569
OFFSET
1,1
COMMENTS
Column 3 of A304230.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +a(n-3) for n>5
EXAMPLE
Some solutions for n=5
..0..1..1. .0..0..0. .0..0..0. .0..1..1. .0..0..1. .0..1..1. .0..0..0
..1..0..1. .0..0..0. .0..0..0. .1..0..1. .0..1..0. .1..0..1. .0..0..0
..1..1..1. .0..0..0. .0..1..0. .1..1..1. .0..0..0. .1..1..1. .0..0..0
..1..0..1. .0..0..0. .0..1..0. .1..1..1. .0..1..0. .1..0..1. .0..1..0
..0..1..1. .0..0..0. .0..0..0. .1..1..1. .1..0..0. .1..1..0. .1..0..0
CROSSREFS
Cf. A304230.
Sequence in context: A328109 A000211 A059902 * A068982 A317530 A171021
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 08 2018
STATUS
approved