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A252691
Number of (n+2) X (4+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
394, 519, 407, 1480, 2048, 6246, 12740, 35128, 84680, 225000, 573968, 1508116, 3915680, 10257360, 26778908, 70099888, 183333200, 479875356, 1255786736, 3287174320, 8604199916, 22523755824, 58961898416, 154354406332, 404082593744
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*(394 - 1451*x - 612*x^2 + 5855*x^3 - 1561*x^4 - 2996*x^5 - 8637*x^6 + 7904*x^7 + 8428*x^8 - 9340*x^9 + 2104*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..1..0..0..2....0..0..1..1..0..1....0..1..1..2..2..3....0..1..1..2..2..1
..0..2..2..3..3..2....2..3..2..3..2..3....2..3..3..0..0..1....2..3..3..0..0..3
..3..1..1..0..0..1....2..3..2..3..2..3....0..1..1..2..2..3....2..1..1..2..2..3
..0..2..2..3..3..1....0..1..0..1..0..1....0..3..3..0..0..1....0..3..3..0..0..1
..3..1..1..0..0..2....0..1..0..1..0..1....2..1..1..2..2..1....2..1..1..2..2..3
..3..2..2..3..3..2....2..2..3..2..3..2....0..3..3..0..0..3....0..3..3..0..0..3
CROSSREFS
Column 4 of A252695.
Sequence in context: A172931 A172710 A236234 * A051986 A223908 A251256
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 20 2014
STATUS
approved