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A302317
Number of nX3 0..1 arrays with every element equal to 0, 1, 2 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
4, 20, 65, 281, 1144, 4321, 18093, 72746, 285199, 1170837, 4701572, 18728977, 76116025, 305826310, 1226299079, 4959269105, 19941716260, 80172499973, 323467010101, 1301467854854, 5237685581779, 21109227250621, 84964283025692
OFFSET
1,1
COMMENTS
Column 3 of A302322.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) +3*a(n-2) +30*a(n-3) -88*a(n-4) -36*a(n-5) -60*a(n-6) -116*a(n-7) +4*a(n-8) -16*a(n-9) +20*a(n-10) +40*a(n-11) +64*a(n-12) +16*a(n-13) -32*a(n-14)
EXAMPLE
Some solutions for n=5
..0..0..0. .0..1..0. .0..0..1. .0..1..1. .0..1..0. .0..1..1. .0..1..1
..1..0..1. .1..0..1. .1..0..0. .0..1..0. .1..0..0. .0..0..1. .0..0..1
..0..1..0. .0..1..0. .0..1..0. .0..1..0. .0..0..1. .0..1..0. .0..1..0
..0..0..0. .0..1..0. .0..1..0. .0..0..1. .0..1..0. .0..1..0. .1..0..0
..1..1..1. .0..1..0. .1..1..0. .0..1..1. .0..1..0. .0..0..0. .0..0..1
CROSSREFS
Cf. A302322.
Sequence in context: A131479 A194094 A055538 * A319779 A287244 A344993
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 05 2018
STATUS
approved