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A302369
Number of 3Xn 0..1 arrays with every element equal to 0, 2, 3 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
4, 2, 31, 20, 154, 284, 1109, 3472, 12763, 48721, 190256, 770983, 3134572, 12931018, 53433431, 221779682, 921445395, 3833216521, 15953742306, 66423173327, 276603513242, 1151978426752, 4797997758989, 19984422198978, 83240190604547
OFFSET
1,1
COMMENTS
Row 3 of A302367.
LINKS
FORMULA
Empirical: a(n) = 6*a(n-1) +a(n-2) -47*a(n-3) +13*a(n-4) +158*a(n-5) -30*a(n-6) -242*a(n-7) -62*a(n-8) +224*a(n-9) +26*a(n-10) +11*a(n-11) +64*a(n-12) -114*a(n-13) -27*a(n-14) +26*a(n-15) -6*a(n-16) for n>18
EXAMPLE
Some solutions for n=5
..0..0..0..1..1. .0..0..1..1..0. .0..1..0..0..0. .0..1..1..0..0
..1..0..0..1..1. .0..0..0..1..1. .0..1..0..0..1. .1..1..1..0..0
..0..0..1..1..0. .1..0..1..1..1. .1..1..1..0..0. .0..1..0..0..1
CROSSREFS
Cf. A302367.
Sequence in context: A353750 A093991 A030447 * A317899 A076936 A344536
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 06 2018
STATUS
approved