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A302417
Number of 4Xn 0..1 arrays with every element equal to 0, 1, 2 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
8, 81, 120, 259, 698, 1650, 3655, 8544, 20246, 47274, 110507, 259419, 607197, 1420291, 3328378, 7799749, 18264688, 42776207, 100206573, 234721284, 549779626, 1287794595, 3016512620, 7065696896, 16550376724, 38767164617, 90806809133
OFFSET
1,1
COMMENTS
Row 4 of A302415.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) -3*a(n-2) +6*a(n-3) -6*a(n-4) +3*a(n-5) -6*a(n-6) +a(n-7) -14*a(n-8) +9*a(n-9) +4*a(n-10) +2*a(n-11) -4*a(n-12) +2*a(n-13) +8*a(n-15) -4*a(n-16) for n>21
EXAMPLE
Some solutions for n=5
..0..0..1..0..1. .0..1..1..0..0. .0..1..1..0..0. .0..0..1..0..1
..1..0..1..1..0. .0..0..1..1..1. .0..0..1..0..1. .1..0..0..0..1
..0..1..1..0..1. .1..0..1..0..1. .1..0..1..1..0. .1..0..1..1..1
..1..0..1..0..1. .0..0..1..0..0. .0..0..1..0..1. .1..0..1..0..1
CROSSREFS
Cf. A302415.
Sequence in context: A210134 A274855 A301939 * A227227 A303184 A302325
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 07 2018
STATUS
approved