A252301 Number of (n+2)X(4+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 1 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 1 3 6 or 7

2670, 1992, 2287, 3032, 5117, 7489, 10626, 18971, 28579, 41037, 74183, 112451, 162093, 294327, 447155, 645357, 1173623, 1784435, 2576493, 4688247, 7130483, 10297197, 18741623, 28508531, 41172333, 74944887, 114008435, 164657517

Offset

1,1

Comments

Column 4 of A252305

Links

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

Formula

Empirical: a(n) = 7*a(n-3) -14*a(n-6) +8*a(n-9) for n>18

Example

Some solutions for n=4
..1..1..1..1..1..1....0..3..3..0..0..3....1..0..2..1..0..2....1..3..3..0..0..0
..3..2..1..0..2..1....2..1..3..2..1..0....1..2..3..1..2..0....1..3..2..2..3..2
..1..2..3..1..2..3....0..1..2..0..1..2....0..0..3..0..3..3....2..2..3..2..2..3
..1..1..1..1..1..1....0..0..3..3..0..3....1..0..2..1..0..2....1..3..3..1..3..3
..0..2..1..0..2..1....2..1..0..2..1..0....1..2..0..1..2..3....2..3..2..2..3..2
..1..2..3..1..2..0....0..1..2..0..1..2....0..3..3..0..3..0....2..2..3..2..2..3

Crossrefs

Sequence in context: A019424 A151813 A010088 * A250855 A235253 A309762

Adjacent sequences: A252298 A252299 A252300 * A252302 A252303 A252304

Keyword

nonn

Author

R. H. Hardin, Dec 16 2014

Status

approved