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A302890
Number of 3Xn 0..1 arrays with every element equal to 0, 2, 3, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
4, 2, 37, 53, 197, 818, 2548, 10926, 42671, 176119, 742413, 3138038, 13445806, 57784846, 249318271, 1078199427, 4668892009, 20238323768, 87777824464, 380862666946, 1652959447763, 7175063435815, 31148370485509, 135230298285690
OFFSET
1,1
COMMENTS
Row 3 of A302889.
LINKS
FORMULA
Empirical: a(n) = 7*a(n-1) -5*a(n-2) -39*a(n-3) +8*a(n-4) +198*a(n-5) -56*a(n-6) -411*a(n-7) +6*a(n-8) +646*a(n-9) -35*a(n-10) -602*a(n-11) +26*a(n-12) +413*a(n-13) -25*a(n-14) -114*a(n-15) -18*a(n-16) for n>17
EXAMPLE
Some solutions for n=5
..0..1..0..0..1. .0..1..0..0..1. .0..0..0..0..0. .0..0..0..1..0
..0..1..0..0..1. .0..1..0..0..0. .0..0..1..0..0. .0..0..0..1..0
..0..1..0..0..0. .0..1..0..0..0. .1..0..0..0..0. .0..0..1..1..1
CROSSREFS
Cf. A302889.
Sequence in context: A078758 A364878 A102015 * A307974 A303625 A123850
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 15 2018
STATUS
approved