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A302376
Number of nX3 0..1 arrays with every element equal to 1, 2, 3 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
1, 15, 76, 475, 2771, 16451, 97160, 574671, 3397622, 20089993, 118787443, 702368950, 4152971123, 24555730380, 145193342488, 858500551625, 5076149984859, 30014306641852, 177468870003729, 1049339576968817
OFFSET
1,2
COMMENTS
Column 3 of A302381.
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) +13*a(n-2) -5*a(n-3) -28*a(n-4) -11*a(n-5) +11*a(n-6) +4*a(n-7) +6*a(n-8) +24*a(n-9) +16*a(n-10) -32*a(n-11)
EXAMPLE
Some solutions for n=5
..0..0..1. .0..0..1. .0..0..1. .0..0..0. .0..0..0. .0..0..1. .0..0..1
..1..1..0. .0..1..1. .1..1..0. .1..0..1. .1..1..1. .1..1..1. .1..1..1
..0..0..0. .0..0..1. .0..1..0. .1..1..0. .1..1..0. .0..0..0. .0..1..0
..1..0..0. .1..1..1. .1..0..1. .1..1..0. .1..0..0. .0..0..1. .1..0..1
..1..1..0. .0..0..1. .0..1..1. .1..0..0. .1..1..1. .1..1..0. .1..1..1
CROSSREFS
Cf. A302381.
Sequence in context: A212093 A212241 A000477 * A041430 A156941 A205440
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 06 2018
STATUS
approved