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A302011
Number of 4 X n 0..1 arrays with every element equal to 0, 1, 2 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero.
1
8, 128, 1808, 25808, 369040, 5276816, 75450768, 1078839952, 15425887120, 220568403088, 3153816694160, 45095125134992, 644796609413008, 9219680980164752, 131828418659815824, 1884960228421653136
OFFSET
1,1
COMMENTS
Row 4 of A302010.
LINKS
FORMULA
Empirical: a(n) = 13*a(n-1) +20*a(n-2) -16*a(n-3) -64*a(n-4) for n > 6.
EXAMPLE
Some solutions for n=5
..0..0..1..0..0. .0..0..1..0..0. .0..1..0..0..1. .0..1..1..1..0
..0..1..0..1..1. .0..0..1..1..0. .0..1..0..0..0. .0..1..0..1..0
..0..1..0..1..1. .0..0..0..0..1. .0..0..1..0..1. .0..1..1..1..1
..1..0..1..0..1. .0..1..0..0..0. .0..0..1..0..0. .0..0..1..0..0
CROSSREFS
Cf. A302010.
Sequence in context: A303458 A301439 A302006 * A301780 A348804 A316804
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 30 2018
STATUS
approved