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A298448
Number of nX2 0..1 arrays with every element equal to 1, 3, 4, 5 or 6 king-move adjacent elements, with upper left element zero.
6
1, 4, 4, 16, 48, 88, 240, 704, 1600, 4032, 11072, 27392, 68608, 180736, 459776, 1160704, 2999296, 7682048, 19525632, 50081792, 128339968, 327434240, 837861376, 2145583104, 5483266048, 14023229440, 35888758784, 91776090112, 234707222528
OFFSET
1,2
COMMENTS
Column 2 of A298454.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +8*a(n-3) -8*a(n-4) -8*a(n-5)
EXAMPLE
Some solutions for n=7
..0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..1. .0..0. .0..0
..1..1. .1..1. .0..0. .0..0. .1..1. .1..1. .0..0. .1..0. .1..1. .0..0
..0..0. .1..1. .1..1. .1..0. .0..0. .1..1. .1..0. .1..1. .1..1. .1..1
..0..0. .0..0. .0..0. .1..0. .1..1. .1..1. .1..0. .1..0. .1..1. .1..1
..1..1. .1..1. .1..1. .1..1. .1..1. .1..1. .1..1. .0..1. .1..1. .0..0
..0..0. .0..0. .1..1. .1..0. .0..1. .1..1. .0..1. .0..0. .0..0. .0..0
..0..0. .1..1. .0..0. .0..1. .1..0. .1..1. .0..1. .0..0. .0..0. .0..0
CROSSREFS
Cf. A298454.
Sequence in context: A222104 A257613 A223202 * A222144 A342817 A107382
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 19 2018
STATUS
approved