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A232048
Number of 2 X n 0..1 arrays with no element less than a strict majority of its horizontal and antidiagonal neighbors.
1
4, 7, 15, 34, 79, 184, 426, 984, 2274, 5258, 12159, 28117, 65018, 150347, 347661, 803931, 1859013, 4298789, 9940535, 22986529, 53154136, 122913828, 284226412, 657246261, 1519818815, 3514434954, 8126793100, 18792428087, 43455684079
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) - 6*a(n-2) + 7*a(n-3) - 6*a(n-4) + 3*a(n-5) - a(n-6) - a(n-7) for n>8.
Empirical g.f.: x*(4 - 9*x + 11*x^2 - 12*x^3 + 8*x^4 - 3*x^5 - x^6 + x^7) / ((1 - x + x^2)*(1 - 3*x + 2*x^2 - 2*x^3 + 2*x^4 + x^5)). - Colin Barker, Oct 02 2018
EXAMPLE
Some solutions for n=7:
..1..1..1..1..0..0..0....1..1..1..0..0..0..1....0..0..0..0..0..1..0
..0..0..0..0..0..1..1....0..0..0..0..0..0..0....0..0..0..0..0..0..0
CROSSREFS
Row 2 of A232047.
Sequence in context: A119749 A201498 A145970 * A145795 A173657 A213358
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 17 2013
STATUS
approved