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A252694
Number of (n+2) X (7+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
3703, 6483, 727, 12740, 1276, 25382, 2592, 51060, 5944, 103716, 15052, 213524, 41692, 449132, 125580, 979212, 407404, 2261532, 1405516, 5679404, 5082844, 15835820, 19012140, 49190076, 72778060, 167430252, 282915484, 608379116
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) - 2*a(n-2) - 7*a(n-3) + 2*a(n-4) + 6*a(n-5) + 14*a(n-6) - 20*a(n-7) - 4*a(n-8) + 8*a(n-9) for n>10.
Empirical g.f.: x*(3703 - 8329*x - 17799*x^2 + 48719*x^3 - 10255*x^4 + 15663*x^5 - 99398*x^6 + 53844*x^7 + 39864*x^8 - 25728*x^9) / ((1 - x)*(1 - 2*x)*(1 - 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..1..0..0..1..0....0..1..0..1..0..0..1..0..1
..2..3..2..3..2..3..2..3..2....2..3..2..3..2..3..2..3..2
..2..3..2..3..2..3..2..3..2....2..3..2..3..2..3..2..3..2
..1..0..1..0..1..0..1..0..1....1..0..1..0..1..0..1..0..1
..1..0..1..0..1..0..1..0..1....1..0..1..0..1..0..1..0..1
..2..3..2..3..2..2..3..2..2....3..2..3..2..3..2..3..2..3
CROSSREFS
Column 7 of A252695.
Sequence in context: A204525 A204522 A294088 * A184471 A249655 A234186
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 20 2014
STATUS
approved