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.

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

R. H. Hardin, Table of n, a(n) for n = 1..210

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

Adjacent sequences: A252691 A252692 A252693 * A252695 A252696 A252697

Keyword

nonn

Author

R. H. Hardin, Dec 20 2014

Status

approved