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A297459
Number of 3 X n 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 0 or 2 neighboring 1s.
1
8, 19, 92, 285, 1143, 3933, 14817, 52868, 194822, 704284, 2575201, 9352440, 34103042, 124055943, 451921339, 1644897204, 5990104595, 21807171062, 79403933671, 289093577711, 1052597637063, 3832392357045, 13953632474038
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) + 4*a(n-2) - 7*a(n-3) + 8*a(n-4) - 19*a(n-5) + 8*a(n-6) + 2*a(n-8).
Empirical g.f.: x*(8 - 5*x + 3*x^2 - 11*x^3 - 11*x^4 + 8*x^5 + 2*x^6 + 2*x^7) / (1 - 3*x - 4*x^2 + 7*x^3 - 8*x^4 + 19*x^5 - 8*x^6 - 2*x^8). - Colin Barker, Feb 28 2019
EXAMPLE
Some solutions for n=7:
..0..0..1..0..1..1..1. .0..0..1..0..1..0..1. .0..0..0..0..0..0..0
..1..0..0..0..0..1..0. .1..0..0..0..1..0..1. .0..0..0..0..1..0..1
..1..0..1..0..0..1..0. .0..0..0..0..0..0..0. .1..0..1..0..0..0..1
CROSSREFS
Row 3 of A297457.
Sequence in context: A057452 A091560 A061877 * A297696 A242188 A119284
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 30 2017
STATUS
approved