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A304226
Number of nX4 0..1 arrays with every element unequal to 0, 1, 2 or 7 king-move adjacent elements, with upper left element zero.
1
8, 5, 6, 11, 20, 46, 97, 189, 395, 836, 1701, 3492, 7284, 15033, 30913, 63989, 132350, 272947, 563756, 1165374, 2406457, 4969281, 10266751, 21207248, 43798629, 90470888, 186881300, 385997321, 797284757, 1646862265, 3401654354, 7026194587
OFFSET
1,1
COMMENTS
Column 4 of A304230.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +5*a(n-3) -4*a(n-6) for n>8
EXAMPLE
Some solutions for n=5
..0..1..1..1. .0..0..0..0. .0..0..0..0. .0..0..0..0. .0..0..0..0
..1..0..1..1. .0..0..0..0. .0..0..0..0. .0..0..1..0. .0..0..0..0
..1..1..1..1. .0..0..1..0. .0..0..1..0. .0..0..1..0. .0..1..1..0
..1..1..0..1. .0..1..0..0. .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
CROSSREFS
Cf. A304230.
Sequence in context: A365281 A021898 A020786 * A019868 A121472 A117039
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 08 2018
STATUS
approved