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A302410
Number of nX3 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
4, 17, 30, 120, 441, 1431, 4754, 16423, 55848, 188797, 641401, 2181141, 7403533, 25137442, 85383840, 289971604, 984703839, 3344148948, 11357024856, 38568809117, 130981523021, 444820935270, 1510634631331, 5130191496078
OFFSET
1,1
COMMENTS
Column 3 of A302415.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +2*a(n-2) +11*a(n-3) +a(n-4) -18*a(n-5) -14*a(n-6) -24*a(n-7) +52*a(n-8) -4*a(n-9) +8*a(n-10) -24*a(n-11) +24*a(n-12) -32*a(n-13)
EXAMPLE
Some solutions for n=5
..0..1..1. .0..1..0. .0..1..0. .0..0..1. .0..0..1. .0..1..0. .0..1..0
..0..1..0. .1..0..1. .1..1..0. .1..1..1. .1..0..1. .0..1..1. .0..1..0
..1..1..0. .1..1..1. .1..0..0. .1..0..1. .0..0..1. .0..0..1. .0..1..1
..1..0..0. .1..0..0. .1..0..1. .0..0..1. .0..1..1. .1..0..1. .0..0..1
..1..0..1. .0..1..1. .1..0..1. .0..1..1. .0..1..0. .1..0..0. .1..0..1
CROSSREFS
Cf. A302415.
Sequence in context: A163736 A249582 A127547 * A303177 A212756 A031040
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 07 2018
STATUS
approved