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A252689
Number of (n+2) X (2+2) 0..3 arrays with every consecutive three elements in every row and column having exactly two distinct values, and in every diagonal and antidiagonal not having exactly two distinct values, and new values 0 upwards introduced in row major order.
1
96, 142, 204, 519, 1047, 2719, 6483, 16887, 42825, 111655, 288975, 754413, 1965903, 5137567, 13421949, 35100447, 91797087, 240169717, 628416399, 1644575439, 4304194509, 11265951439, 29489332431, 77193738645, 202074840159
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 5*a(n-1) - 4*a(n-2) - 11*a(n-3) + 9*a(n-4) + 12*a(n-5) + 12*a(n-6) - 34*a(n-7) - 8*a(n-8) + 28*a(n-9) - 8*a(n-10) for n>11.
Empirical g.f.: x*(96 - 338*x - 122*x^2 + 1123*x^3 - 34*x^4 - 626*x^5 - 1907*x^6 + 1306*x^7+ 1728*x^8 - 1488*x^9 + 288*x^10) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 - 3*x + x^2)*(1 - 2*x^2)*(1 - 2*x^3)). - Colin Barker, Dec 05 2018
EXAMPLE
Some solutions for n=4:
..0..1..0..1....0..1..1..0....0..1..1..0....0..0..1..1....0..1..1..0
..0..2..0..2....2..3..3..0....2..3..3..2....2..3..2..3....0..2..2..3
..1..2..1..2....2..1..1..2....0..1..1..2....2..3..2..3....3..1..1..3
..1..0..1..0....0..3..3..0....0..3..3..0....0..1..0..1....0..2..2..0
..3..0..3..0....0..1..1..2....2..1..1..2....0..1..0..1....3..1..1..3
..3..1..3..1....2..3..3..2....2..3..3..2....2..3..2..3....3..2..2..0
CROSSREFS
Column 2 of A252695.
Sequence in context: A323629 A146992 A261287 * A253392 A116119 A039600
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 20 2014
STATUS
approved