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A297508
Number of 3 X n 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1 or 2 neighboring 1s.
1
1, 29, 110, 314, 1829, 8803, 34757, 157673, 735144, 3208028, 14196017, 64154943, 286007061, 1271032033, 5685858000, 25403326244, 113255416409, 505585282497, 2257780807909, 10075966019543, 44971626813134, 200763429520862
OFFSET
1,2
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) + a(n-2) + 32*a(n-3) - 15*a(n-4) - 65*a(n-5) - 74*a(n-6) + 56*a(n-7) + 24*a(n-8) - 3*a(n-9) + 12*a(n-10).
Empirical g.f.: x*(1 + 26*x + 22*x^2 - 77*x^3 - 136*x^4 - 18*x^5 + 80*x^6 + 21*x^7 + 9*x^8 + 12*x^9) / (1 - 3*x - x^2 - 32*x^3 + 15*x^4 + 65*x^5 + 74*x^6 - 56*x^7 - 24*x^8 + 3*x^9 - 12*x^10). - Colin Barker, Feb 28 2019
EXAMPLE
Some solutions for n=7:
..1..0..0..0..0..0..0. .0..1..1..0..0..1..1. .1..1..0..1..0..1..0
..0..1..0..1..0..0..1. .0..0..0..0..0..0..0. .0..0..1..0..0..0..1
..0..0..1..0..0..1..0. .0..0..1..1..1..1..1. .0..0..0..0..1..1..0
CROSSREFS
Row 3 of A297506.
Sequence in context: A044661 A010017 A256648 * A232780 A232787 A232852
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 31 2017
STATUS
approved